Biased answer but I really like the Hiwatt Super-Hi 50. It has absolutely crushing modern high-gain sounds. And because it has a switchable 4th gain stage, you can set up one channel for low gain (or even cleans) with 3 gain stages and the other channel for modern high gain with 4 gain stages. And because the amp is based on the Hiwatt DR504, it can still get those classic rock sounds Hiwatt (and Marshall) are known for.
As long as you don't need an FX loop, it's a great amp. The loop absolutely is the weak link in this amp. It's incredibly noisy.