I currently have an amp from the Stratocaster Starter Pack, a 10 watt failure.

I'd like to invest in a nicer amp, but I went to guitar center and wasn't really satisfied with most of the amps I tried. (Raven, peavey, marshall -- all 30-40 watts)

My price range is under $300, and I play a variety of music, so the amp also has to be versatile. Preferably, any models with nice high gain would be great too.

Any suggestions?
You're looking at Modelling amps here, look at:

Peavey Vypyrs
Vox Valvetronix
Roland Cubes.
I'd give the roland cube 30x a try and the 30 watt vox valvetronix a try.
I don't give a shit if you listen to me or not
I tried out the vox valvetronix. I expected it to have great sound, but the interface was being difficult with me in the store. I've played a smaller, old vox tube amp that sounds okay, but it just didn't have that range of sounds.

Thanks for the advice guys, I'll be sure to check out the roland cube 30x
I have a vox ad30vt for sale, fits what you want perfectly.

Link's in my siggy
05' G&L S-500
95' Godin LGX

96' Yamaha APX 6-A

Peavey Classic 30
Maxon OD808