The best for death metal...Hmmm...
I would have to say that Line6 is good all around. The Spider 112 combo is a VERY good amp, and not too expensive. As an alternative, you can use a home stereo and a distortion pedal.
For a distortion pedal, I would recommend the Digitech XMM Metal Master, it's an amazing pedal. In order to use a home stereo, you either need to have an 1/4" input jack on the stereo or get a 1/8"-1/4" adapter, and go from the output of the pedal into the input jack on the stereo. I did this for awhile, and it was great, but then I killed my speakers (They were old), and all I have now is a shitty little pratice amp.
Whichever way you choose to go, you will end up with great tone. Having such a low budget really sucks, if you had about $1200 to spend, I could give you a nice sized list of excellent metal amps, but oh well. I Hope I helped at least a little bit.