Best basketball game ever. Period.
Anyway though, if you're looking for a realistic NBA Simulation then you need look no further than NBA 2K12. The historic teams featured in this years release are legendary. Hakeem and the Rockets. O'neal and Hardaway's Magic. Larry's Celtics. Jordan and Pippen's Bulls. Magic's Lakers. The list goes on and on.
The physics that you see from time to time when the ball bounces off the rim, then off the backboard and finally through the net are amazing. I had to mention this since i haven't seen anyone else bring it up before. Part of the reason that i mention the ball physics in NBA 2K is because the extremely obvious non existent physics in the NBA Live series. If i shoot a leaner going out of bounds on the sideline from the three point line, i expect to see the ball go through the net in a realistic lifelike motion, and that's exactly what NBA 2K gives me.
Sure NBA 2K12 has a few minor glitches and buggy animations from time to time, but you would be hard pressed to let it affect your decision on whether or not this is the best basketball game ever made.