For a non tube Amp IMO the Tech21 Trademark 60 can't be beat. Especially if you're playing blues. It cuts through and you can play pretty much ANYTHING with it. This video is a bit boring but you will see the potential of the amp. http://www.youtube.com/watch?v=ZG6ca8w802c For the guy looking for a Metal focused amp this one will also do the trick. Although not really voiced for modern metal you can tweak it and get surprisingly good results. I gig with this a lot. especially when I need to just grab and go for a pick up gig. It's really simple to get a good tone, Has an effects loop and goes direct into the board as well. the Boost feature is AWESOME for bumping up those solos.

I own a few Line 6 products, Personally I think they have trouble cutting through the mix unless you're willing to spend Hours messing with them. Not Worth it IMO. Great for home recording. Useless on stage. Just My Opinion.

For Small Tube amps I really love My Hayden HGT 20 (My WHAT?) Watch the video below. I also like the Hayden MOFO's they come from 15W to 100W and let me tell you the 15W into a standard 4x12 cabinet will rip your head off. So before you go thinking you need lots of wattage. You really don't. Surprisingly these are all tube amps designed by Dave Green in England yet they are still in your price range. They can be a bit tricky to find in the states. If anyone is interested in them I can find you a dealer. Just PM me.
http://www.youtube.com/watch?v=effAJNybgyY