Myself, I take a slightly different tack. The fact is that the crazed intensity of the best two young slashers in the L going head to head, or the deleriousness of Staples as Kobe goes for 22 in the 3rd quarter is noteworthy because it is so rare. One of the things we forget watching tourney games is that they are neutral court games. Just for the heck of it, I rewatched the first Villanova-UConn game from this year on the DVR (definite "save until I delete status"), and I was struck by the rabid intensity of the crowd, and the game wasn't even played on campus. Aesthetically, 5,000 drunken college students tends to add to the experience.
Plus, as much lip service as NBA players give to "every game mattering" anyone who watches often knows that this is BS. Each team has at least 10 games a year that they basically phone in (and given the schedule, it's almost inevitable.) This dynamic is even more clear in person, where you can often tell in the first 6 minutes that one team (usually the visitor) is just not with it tonight, and extensive gar-bage time could ensue, as Marvelous Marv might say. Over the course of a 35 game college schedule, finding a reason why each game is 'special' is not as much of a stretch: there are rivalries, hated players, must-win-to-get-into-the-tourney situations, the big bullies going into a hostile gym (my favorite games), and so on.
Finally, the college game just sounds different. Even in tournament games there is a particular moment, when one team is on a run, perhaps has just hit a 3 to cut a lead to 2. As the other team brings the ball up the floor, the point guard comes to half court to meet him, gets down in his stance and starts clapping. There's a particular roar at that moment, that you almost never hear in the NBA.
I'm not going to claim that the college game is better, or more skilled, or any nonsense like that. I am still going to claim that from an excitement standpoint, I'd rather watch a regular season D-I game over most NBA games (Phoenix games largely excluded at this point. Boris Diaw is in my current 5.*) Now the playoffs (Playoffs!?!?!?), that's another story.
* Just to keep track, I think I'm going to have to keep a tally of my "five on the floor". Right now
PG - Jason Kidd. 12 wins and counting, carry on.
SG - Kobe (I still hate him, but that 3rd quarter was pretty sick.
SF - Boris Diaw
PF - KG. Please stay in the Mini-Apple.
C - Joakim Noah. Go Gators (blech).