And the can was opened...
I like Sovteks, and I like J.J. Tesla. I run them in my Mesa gear and have no complaints.
I played a
Fender Twin with
Electro Harmonix tubes that sounded fine as well.
You can try
http://www.partsexpress.com or
http://www.eurotubes.com
There are a LOT of opinions about which tubes sound best, but the frequency at which people change their tubes doesn't normally give them a chance to compare. When you need to change them, it is due to them sounding like crap, so when you drop a new set in, it's like magic.
At any rate, both sites give comparisons of brands so you can make your own opinion.
Have fun !
Bamm