Buy the Criterion version. This DVD set has amazing picture quality, and extras that are simply too unique not to pick up.
I have no idea when this title is going OOP with Criterion, but if you like the film even a little bit, buy this version before it does go OOP. The commentary track with Laila Nabulsi and Dr. Hunter S. Thompson is worth the 40 dollars alone, IMO.
However, one thing you ought to take into consideration, if this is a big deal for you -- the set does feature both a Dolby Digital 5.1 and DTS track, however both of these tracks are absent the foley effects in the center channel. This is Universal Picture's doing, as Criterion was simply supplied with the elements. They did not actually DO the mixing. However, as with most Criterion discs, the original sound mix is present, in this case Dolby Digital 2-channel which decodes nicely via Dolby Prologic II. This track is fine.
In short, BUY BUY BUY this disc. You will not regret it.
I actually got mine from here at HTF by trading a few titles that I had upgraded. Even if you only somewhat liek the film, the DVD is one of Criterion's best and one of the top special editoons out there.
Just because it was pointed out earlier that the Criterion has awesome PQ, DVDBeaver did a comparison between the regular release and the Criterion and found that they look almost exactly the same.
If you like more features and such, go with Criterion's. If not, go with the other one. In my case, I own the Criterion one!
It also has to deal with how much money you're willing to spend. Although I found Criterion to overcharge their products sometimes... It's really up to you.