Yeah, the college v NBA is an interesting one. I've been watching plenty of college the last week or so (pretty much 2 games every day on NASN Setanta here in the UK) and last night I taped the Wizards 76ers game. College games are so intense, everyone goes full on 100% the whole time, crowds are full on, packed stadiums, amazing atmosphere. Cut to the NBA, you find a half full stadium, no crowd support to speak of, player going through the motions, no one pressing too hard defensively, the product just isn't as appealing (perhaps that's because it was a Wizards 76ers game - although this was actually not a bad game, great final quarter).
Whenever I watch college I imagine myself out there and think how I wouldn't be able to even get the ball up the court through all the pressure, but watching NBA I reckon I might even be able to get a shot off every once in a while (albeit from a few metres outside the arc).
Conclusion: I'd prefer to see a college game most of the time, unless it was a particularly juicy NBA battle (Suns Lakers for instance).