Randall RD5H Diavlo 5 Watt tube guitar amplifier head
Its small, punchy and the tone is perfect for modern metal.
I use this for recording using the XLR cab simulated output from the Randall head directly to my soundcard and it sounds great.
If you are thinking about it just buy it, you won't get a better metal valve tone anywhere else for anything near bax price of the current £159!