I've just got myself a Fender Stratocaster, and it's my first Electric guitar. I'm looking to buy an amplifier sometime soon, but I'm not really certain what to get. My budget would be around 500 USD. This also cause I'd be looking for a smaller amplifier .. small or small .. but since it's my first I don't have a thirst after a monster-size.

Any ideas about brands / models?

As what comes to my music I do usually play Metallica, Jimi Hendrix, Clapton, System of a Down. I'm more into the slow and emotional rock you could say.

Thanks, William
you might take a look into the modelling amps like a Roland Cube since you play a variety of styles. just stay away from Marshall MG's or Line 6 spiders. you might however start looking at tube amps like the mentioned fender or a Peavey Classic which can be overdriven into metal territory.