It's more of the same if you've played previous versions, but it feels like the polishing for this gen may be done.
Nestled between all the shock value and the antihero shtick is a deep, detailed and enjoyable game of epic length with enough to do to keep even the hardest core gamers occupied for weeks or months. To a certain extent it's hard to separate the quests and the richly populated world and the mostly entertaining storyline from the perverse pleasure of beating old ladies down with a baseball bat or capping some dude off his motorcycle and backing over him with it. The GTA "experience" is tied to the game in some very specific ways.
Still, with such a complex and well thought out system of advancement, questing and open-ended sandbox play, it is conceivable that a non-offensive (or perhaps less offensive) variant of this type of game might be just as fun. One's ability to separate the setting of the game from the game itself may play a big role in the overall enjoyment.
The graphics here are nothing particularly special; we still get the same semi-clunky presentation from GTAIII only here there is more of it. The little touches on the game from the ability to influence your appearance through a variety of wardrobe changes, eating and exercise may seem a little silly--kind of like playing dress up dolls--but it does have an actual function in the game as your physical attributes influence how or whether you can entice certain females in the game to express interest in you. The dating sidetrack can begin and often the result is something useful for you down the road.
The sound is decent with a wide array of sampled clips and mostly decent voice acting from some recognizable Hollywood names throughout. Some of the script is clunky and awkward which even the best talent couldn't salvage but for the most part everyone involved does a good job and helps move the story along.
The story itself is, as expected, a loosely connected series of encounters which sort of form a cohesive narrative as you play. The primary setback to the plot is that there is so much to do in the game which does nothing to push the story forward that you can go for hours upon hours of gameplay time without even touching the quests. This often leads to the story coming across as disjointed, especially when you start finding several possible mission opportunities open simultaneously. You can follow one contact through several missions before returning to a different contact and the second will pick up right where it left off, even if it doesn't exactly make sense for it to do so.
The controls for the game are still prone to the same pitfalls as previous series entries. Namely, combat is difficult even with the auto-aim option and this game more so than previous titles feels full of required combat. Several missions have you sneaking or gunslinging your way into or out of buildings or other locations and with clunky camera controls and imprecise targeting, it can get frustrating at times to try and figure out the best way to approach a particular challenge.
Also, for all the freedom the game allows, once you start off on a mission path the game often puts you on surprisingly rigid rails. Scripted car chases that follow gun battles could be avoided with some well-placed shots but such opportunities are cheated over with temporarily invincible characters and other pseudo-cheap gimmicks that make the cracks in the game's lip service to total freedom show.
Even without the plot or the missions, there is enough to do to occupy even an infrequent gamer for more than the duration of a rental period. Some of the side quests like collecting various objects scattered around the massive map or spraypainting an obscenely large number of tag locations are grueling and almost impossible for a regular gamer to complete without some kind of help or hint guide, but those additions are mostly there for the 100% completion fanboys and don't necessarily add or subtract from the overall enjoyment of the game.
At this point I think we've seen everything Rockstar has to offer from this incarnation of the (in)famous franchise and the depth, attention to detail and polish is probably as good as it is going to get. If you've considered previous GTA titles you can safely skip ahead to this one and get all the best attributes in one package. But at this point I think the welcome mat for the bigger, more incremental upgrade is wearing thin and if the franchise is to be kept alive GTA IV needs to come with something that addresses some of the series' actual flaws instead of trying to cover them up with spit and polish.