ive had both also and also got rid of live and kept nba2k6
i do like them both and wish i would of kept live but its to late now(only reason is this damn trade value is horrific i wont be trading anymore games i buy even if they suck, im not taking a 30-35 dollar hit anymore)
back on topic, i would suggest that it depends what you are looking for
to me live is a better overall game, game play wise. its almost like a basketball sim, playing the computer on the hardest level is a bitch, you have to play like a real basketball team calling plays up and down the court in both offense and defense always finding the open man, never taking wild shots, you have to be very presice
nba2k6 is the same old fun game it always has been
i often found myself frustrated with live
both look wonderful (in HD) yet play very different
if your looking for a sim type game and some tough/rough games, get live
if your looking to have more fun, nba jam type run and gun, go with 2k6