I like two kinds of games best, so let me break it down.

Firstly - FPS - I love Doom, and Half Life, and Turok, games where I'm immersed in a world of combat. I particularly like games like Doom etc, because I don't like fighting enemies like myself, my favorite part of Half Life was when fighting the aliens, not the marines. I like Turok a lot because I'm fighting a lot of big dinosaurs and guerrillas. Turok was great because of the huge boss enemies, lots of fun. I'd like to use this time to examine the best elements of some games, and propose to someone that combining these elements would make for an awesome game experience.

A - Far Cry - The freedom to explore the whole map was great, especially getting the binoculars early on in the game. I also really like the vehicles and the enemy tracking system. Also, objective. Some games leave you blind, with no idea what you're trying to accomplish, and then there are other games where the guy on your radio is telling you every step of thw way what to do. I like how in the game you're told what to do, but not how to dot it, and you always know what your current destination is, but it's up to you to get there, I'm not lost nor am I babied.
B - Thief 2 - This had the best level design ever. Each level was realistic, the stealth was accurate, if you could incorporate the scale of far cry into a Thief game, you'd have an awesome game.
C - Half Life - The fact that the story was told entirely from a first person point of view, and control of the character was never taken away from you made the immersion into the world unbelievable. The AI was great also.
D - FF7 - Not a FPS, I know (obviously) but the scripting of how you could conceivably explore the entire world if there were not rivers and mountains in your way, you see places you can't get to yet, and the acquisition of vehicles to explore this terrain, one piece at a time, finally ending in a flying machine with which you can go anywhere was amazing.
E - Hexen II - The level design in this game, particularly the puzzle solving aspect of it, was phenomenal, especially in the first world. I enjoyed solving puzzles from reading the butchers journal, etc. I also think the medieval castle was just fun to explore. It's just more fun to walk through places that seem real than to be wandering corridors of a random dungeon or cave.
F - Parasite Eve II - Realistic puzzle solving in this game is beyond any other. This is a element that should be employed by both FPS and Survival horror.
G - Turok - The weapons were fun, a FPS needs to pace the weapon acquisition. Also, having large enemies like the Triceratops was cool, although this game was a bit too early for huge enemies, and Half Life added to that. The key collection was awesome here too, allowing for back tracking.
H - Goldneye - Leaving multiplayer aside, the cheats on top of this already awesome game gave me a reason to finish each level on the highest difficulty level.
I - Shadows of the Empire - The Jedi difficultly level was realistic. One laser blast and a storm trooper was down, one from a storm trooper and you lost between 30 and 50 health.

I'm sure I'll be able to think of more as time goes by, but by combining all these elements into a new FPS we might be able to create my perfect game. Two other elements which I haven't really seen in any other games are listed here.

J - Real World Environments - Although Half Life and Hexen felt real, I'd like to see someone take the blueprints of a office building, or a nuclear power plan or something of that nature, put it into the computer and make a game out of it. Add dramatic elements based on what already exists. Cause the stairwell to break so I can't get to the top 3 floors, but have to climb the elevator shaft to the roof to repair the elevator, and when I do that all public floors are accessible, and then find a key in the janitors closet and use it to access the basement or something like that, realistic puzzles in a realistic environment that makes sense.
K - The challenge - I get more replay value out of games like this when they add a difficulty level that unlocks something, but it's even better when the difficulty level involves getting more weapons to kill many more enemies. It's still harder, but I'm not scrounging for ammo.

So now someone needs to combine all these elements to create the best Single Player FPS experience ever.

Secondly - RPG's - I love Chrono Trigger, for many of the same reasons that I love Half Life. The similarities are really there, and many of the same elements found in a good FPS should be found in a good RPG. Firstly, the games should involve a freedom to explore a world that seems realistic and worthy of exploration. Secondly, there should be an objective, just like in FPS I want to know what I need to accomplish, but I want to accomplish it myself. Thirdly, acquisition, while in FPS you get new guns, in RPG's you get weapons and skills and level up, and just like in FPS these need to be timed well. Lastly, combat, if the combat engine is boring or stupid, I don't like it, thats what makes Chrono Trigger the best RPG of all time.

A - Chrono Trigger - From the above elements, the only thing CT is missing is more unlockables. I'd like to see some hidden characters, or more places to explore, but really, CT is near perfect. I just want more. The elements that this game had that none other has been able to capture are the double and triple attacks, the non-random battles that take place on the same screen as you explore on, and the ability to acquire a character that you originally thought was the big boss.
B - Super Mario RPG - See above. It's really only missing Luigi and Toad, if those two characters were in the game somewhere, this game would be perfect.
C - The Legend of Zelda, Link's Awakening - This game is a triumph of the elements of seeing some place you can't get to yet. It's a great feeling to be able to see some places that are inaccessible, then get an item that allows you to access these places, and then go explore them. All RPG's need this.
D - Morrowind - Ultimate open ended exploration. This game needed some more emphasis on the objective, but it was always there for you, I never felt lost. Being able to grow and develop my character as I saw fit was great.
E - Dungeon Siege - Leveling up Characters by having them get better at whatever it is that they're doing is the best way to do it. That way you aren't able to get better at negotiating by fighting.
F - Diablo (and D2) - The ultimate in acquisition. Getting new items almost never gets old, and some of the best are really really hard to find.
G - Aidyn Chronicles - Despite poor graphics, and mediocre combat, the ideas and vision this game has are amazing, unlike any other I've ever played.
H - Fable - Ways to play like Morrowind, Fable gave you a lot of options about what ways you want your character to grow. This game was a lot like the Sims, in that you had stats which developed, and your character would grow based on these stats, and people would react to you in ways that these stats would reflect.
I - GTA 3 - The 'Hidden' stats are the element which needs to be employed by this game, namely your stamina. If you run a lot and exercise, you will be able to run for longer periods of time before your stamina runs out. You never see any numbers attached to your stamina, but they are there. Originally, Fable was going to use hidden stats, so that you're strength etc were governed by numbers, but they changed that.
J - Knights of the Old Republic - Like Fable, this game let you choose good or evil, and based on that decision, characters would react to you differently. This was not as large scale as fable, but had a more dramatic effect on the end of the game
K - Ultima IV (for NES) - This game was as open ended as Morrowind, but was released in the 80's! You're given an objective to accomplish, helped along the way, but it's entirly up to you how you choose to do it. It is without a doubt the best way to play a game. If game makers would look to this game and remake it using modern graphics etc, it would be the hottest ticket item ever.

Again, I'm sure there are more than this, but this is the best of the best. The most important element however, is gameplay, and to develope good gameplay a programmer needs to employ these elements, but they all revolve around objective. Give players a destination, and allow them to reach it themselves, by allowing them to go in directions that aren't the right ones, give them reasons to explore, and keep the pace of the game through aquisition, and keep the development of plot through the puzzles to be solved realistic. This is why without any doubt, Chrono Trigger is the best game of all time.

If, anyone knows of any games that I would like to play that haven't been mentioned above, pleas drop me a line and let me know.