i play out of a fender showman w/ a 2x15 cab. i like it better than the bass"men" i've played. i swear by this amp. i think it sounds like god is smiling sunshine on you. i use it for guitar in one band (only amp i've played that can handle the octave pedal i have without breaking up or farting the low notes) and it gets used for bass in another. plenty loud for both applications. i've had many ooh's and aahh's bestowed upon me when people hear it for the first time.

The ampeg v-4s are great for both, but pretty dirty. If you want something clean (and cheap), maybe check out a Sunn Colliseum (around $200). Some 2x15 cabs sound great for bass, are usually a lot cheaper than 4x12s and can be pretty clean and brite too (but not brittle). I've got a Peavey 2x15 that sounds pretty good for guitar and great for bass. I've seen them around for $150.

I own an Acoustic 470 amp from the seventies. Its has a switch that changes the amp from a bass amp to a guitar amp. I use it mainly for bass (for which it sounds amazing) and supposedly the guitar end is pretty decent. Its the same amp that John Paul Jones used in Led Zeppelin in the mid seventies. I love it.

I play guitar (and bass, occasionally) and had this old broken Bassman amp head laying around for years. I finally spent some time recently and repaired it.

It sounds incredible, particularly for guitar. I can't imagine anything sounding bad through it. As much as I like my old Deluxe, this blows it away. If you can find a deal on a used one, go for it.

I would also recommend a kustom head or combo. The old ('75~'82) kustom heads sound great for guitar or bass, and were made for this purpose...along with the cabs and are really cheap. I recently got a new kustom quad 100 hd head. It's great for guitar, and just recorded some bass tracks today through it running into an older randall 4x12. Full spectrum. The head also has a line out built in and makes for a pretty nice direct.
Doesnt have that classic kustom crunch but has some very distinct distortion (great if your looking for something aside from that over used marshall tone.)
And they are cheap, about $250.00-300 brand new.

-Darrill