Another vote for the MV 50!
Yep, you can get them at Pep Boys for about $60, sometimes on sale for less.
I've used mine many, many times. It even comes in a cool little bag to carry around in, and wit hseveral fittings; everything you need. It does get pretty hot running constantly, but hey that's the way phsyics works. For teh money, you can't beat it.

But, I got a certificate for a huge discount on an ultimate Air CO2 system so i'm probably changing to that. If you're willing to spend a little more $$, having a CO2 canister can have a lot of advantages in emergency situations... enough push to reseat a bead on-trail, running air tools, gas for welding, etc etc.

 

Turned out I didn't get extended warranty so I opened her up. The lead off the switch came unsodered (?sp). So resodered and will have to better cycle in of cooling periods. All things considered this thing gets used often so for what I paid I'm happy. I air down to 5-10psi and air up to 32-35psi with 33/12.5/15's every time I wheel.