NBA 2k11 or Black Ops?

I want to know from experience and online play, black ops will only do online, no campaign, i want to know y each one is good and which u prefer. Its time for me to get a new game in a couple weeks and traditionaly i play against m older bros ociation team in all the bball games, but black ops looks rl cool cause im playing mw2, so plz explain y...thx! (MOST PErSUADING ANSWER GETS 10 POINTS)