A breath of life in an otherwise tired genre. Nothing to write home about though.
* Early levels - The aura of change in Rift is enough to power you up to level 15 or so solely in its own merrit. Coming from different MMOs, you will find the best aspects of those all piled in here, but the subtle changes and feeling of new and exciting do kind of grab you. The starting areas are pretty secluded, populated, and generally full of lots of Rift fighting action.
* Cities - I have only found one main city (Meridian) and I'm not sure if there are others (currently level 31). Meridian is boring, small, and sometimes confusing. There is a main tower there with a teleporter that teleports you up and down one level at a time. This is very annoying and you will find yourself having to go into this tower of boredom many times. It just doesn't feel like a place I want to be, or a place I can call "home".
* Dungeons - Having only done two dungeons I cannot speak towards the overall satisfaction you personally may get from them, but I find them somewhat uneventful and essentially zerg-fests. Beautifully rendered, but lacking in intensity.
* Class systems - Here lies the bread and butter of Rift for me. You choose your main "calling" and are then prompted to choose 3 out of 8 souls to populate your soul tree. As you level, you will find quests to acquire the other 5 souls that you did not pick at first, allowing you to experiment with all soul builds with just one character. This system provides a very wide range of possible classes, but some have run into a problem having simply too many abilities to choose from. The soul system is very fun, and not being herded into one specific build is a nice change from MMOs past.
* Rifts - The namesake of the game. It is.... Well, hit or miss. In early levels Rifts were dominated by groups of about 70 players. This provided absolutely no fun and was basically a loot fest. As I progressed into higher level territory and the population thinned a bit, Rifts became much more fun. A group of 3 or 4 fighting waves of elites provides a nice challenge, and generally you will find smaller groups make for more fun in this game.
* Instanced PvP - The two battlegrounds I am able to access at my current level are OK. In one, your team has to control a "fang" in the center of the map and the longer you hold it, the more damage it does to the holder, eventually killing that person. An interesting mode. The other is more of a "domination" type game mode. 5 points around the map are needing to be controlled. The more you have, the more points you gain. Nothing groundbreaking here.
* World PvP - Ahhh the bane of our existance, world PvP. I never had much luck in PvP in other games, always kind of just being stunned to death. In Rift, everyone seems very even. World PvP is pretty active currently, and many zones are shared between factions. My only gripe with the current state of world PvP is that it is essentially useless. You cannot take over towns (even though there is a 'wardstone' feature that serves as a sort of base, spawning NPCs) and you get no 'favor' (currency) for killing players. Its a fun time, but the appeal wears off very quickly.
* Graphics - Very good. Mountains look mountainous, water looks like water and not glossy reflective perfect CG water, and generally all textures and effects look very good.
* Exploration - My favorite part of the game. See those mountains over there? There is actually stuff to find when you climb it! Puzzles, cairns, acheivements! The exploration side of the game is awesome, as you are always finding new stuff tucked away in a mountain or cave.
* Artifacts - A nice "side job" if you will while you go about your Rifting life. Collecting artifacts (glowing orbs in the world, sometimes hidden, sometimes not) and adding them to a certain set, and then finishing that set by collecting all artifacts requires, nets you some currency with your main city to buy mounts, pets, and other vanity items. A nice little addition to break the linear form of MMO gaming.
* Guilds - Completing guild quests allow you to level your guild and spend points on improving various functions of the game, ie: more rift loot, instant raid rez, etc... Some of the "perks" are utterly useless, such as the banner perk, which requires you to buy a one use banner reagent that costs 1 plat (a decent amount of money) and increases a certain stat minimally for 3 minutes. Useless, and dumb. There is currently no guild bank.
* Crafting - I am enjoying professions in this game moreso than any other. For some reason it is just enjoyable, easy, and not so tedious and bank breaking. As of now at level 200/300 armorsmithing, I haven't had to buy one obscure mat or pricey item from another crafter. Everything you need to craft is easily attainable through things that you are already doing. A nice change from the sometimes completely overbearing crafting requirements of other games.
* No add-ons!!!! - There are currently no add-ons for Rift, and Trion has stated that they will not allow it. That means... No e-peen losers, gear score, etc. Just you and your friends working through content as it was intended to be. Challening and fun!
Overall the game is fun. It's a nice change of pace from what everyone is used to with an MMO. Do I think about it all day and get giddy with anticipation about running home to play it? Not at all. In fact as I write this I haven't played for two days. When I do sit down and play I often find that I do so for hours on end, which is a testament to the fun factor Rift can bring.
It is really up to your own personal tastes. I find the game to be enjoyable enough to spend a day or two a week playing, but I honestly just think my days as an MMO hermit are just over. If I would have to have picked an MMO to play during my prime years of raiding, etc... It would have been this over WoW.