You don’t even need to ask! Generally speaking, you don’t want a guitar amp to sound nice, you want it to sound good, good being a function of many things.

For clean sound, use compatible radio preamp tubes and bias the power tubes conservatively.

For distorted sound, use the lowest overhead preamp tubes you can find, and bias the power tubes as hot as you dare without them breaking within the hour. You can always change them after a gig, or between sets. :-)