I use a Trace Elliot right now. I love how versatile it is. I can get a great, modern sounding tone out of it, and then tweak a few settings and get what I need for Jazz ensemble. Green LED's are a nice touch too.
I'm looking into getting a Markbass setup. I played through one a few weeks ago and loved it! it's basically what I get out of my Trace, but lighter.
Before all this, I used Ampeg. Great amp. The only reason I don't use it anymore is because it was my brother's so I couldnt use it 24/7.
One of my teachers played through an Acoustic Image head and an Epifani Cab. He also used a Fodera, so the bass did a lot of work too, although that is a fantastic combo.
Warwick makes great amps too, but for that quality, the asking price is too high.
In short, I like these amp manufacturers:
1: Trace Elliot
2: Markbass
3: Eden
4: Warwick
5: Ampeg (higher end and legit vintage Ampegs)
6: Epifani (but there have been problems with different brand heads with their cabs i heard)