Grand Theft Auto 3. I played the game for months before I beat it. Litterally, months. Sure the blowing the hell out of random shit didn't help any with time. But it sure was fun. Halo 3 on the other hand, well, I beat it on legendary, in a day. The game play is glitched, and failed compared to Halo 2, by all means.
It's Halo 3 vs Grand Theft Auto 4...
Anyway, Halo 3 is a decent shooter, With a decent story, Decent AI, Shite graphics. Basically all round average, Except for the online multiplayer, Which is fun as hell, As long as you play it around 3am to 7am, So you don't get silly little children playing, Who scream obsenities down their microphones because they were killed. Halo 3 isn't anywhere near as good as the first 2.
Grand Theft Auto 4, Where to start? An amazing story, With double crossing, Back stabbing, Multiple chioces, Friendships, Relationships. It isn't your usual "rag's to riches" stories of GTA's of past, It's a very gritty, real, And at times, Heartbreaking. The graphics are simply sublime, Everything has texture, And life, Even the trash around the city. The psyhics in this game are breath taking, You hit a curb while riding a motorbike, You will come off, And you will go rolling down the road until something stops you, Or you lose momentum.
Simply put, GTA 4 is a WHOLE lot better than Halo 3.