GTA... In the early years!
Gameplay- The gameplay in Mafia is good. You have to drive the speed limit and obey all stoplights, but it's still pretty fun. Actually, this makes the game feel more realistic. When killing, you can lock on to targets, making the game better (Shooting wise). The free-drive mode isn't really that fun, unless you like being able to spin people out and stuff like that, so I'd suggest sticking to the missions.
Missions- Mafia has a nice variety of missions. The storyline that goes along with them is well thought out and almost makes the game best. They're challenging and have neat objectives to them, making them a lot more funner. Rather you're driving people around, killing other mobsters, or smashing stuff up, you're sure to find most of the missions in this game fun.
Graphics- The graphics in this game are awesome! They really give you the feel of New York in the early 1900s. The PC version of the game hands down has the absolute best graphics, followed by the ones on the other systems.
Mafia is a game definently worth a rent, and a buy, depending on how much you like it. I'm very impressed with it.