For anyone that has a basement, finished or not, what ceiling light fixture does it use? (not including table lamps or portable plug-in fixtures).

Basement is finished.
Its nearly all fluorescent. Was originally all T12 (LPF RS ballasts), but some have since been upgraded to T8 (electronic ballasts). And one got LED'ed when the T8 ballast died.

I've never lived in a house with a basement.  My crawlspace has a single porcelain pull-chain fixture with a 135w incandescent light bulb near the access hatch.  For working away from that, I used to use a pair of 100w quartz halogen work lights powered by an extension cord that I could drag around where needed, but the bulbs have failed on those.  I now use a cordless LED work light instead.

A bit of a mix of lighting, the basement is all finished.

There's a section with a drop ceiling and 3x 2x2 parabolic troffers that use 3x F17T8 lamps. One F96T12 strip with a wireguard, I mostly installed that one to get it out of the way. Then in the bathroom I have a 2x F17T8 wallbracket over the mirror.

Then in a couple of the utility rooms I have some 4ft and 2ft fluorescent strips.

At my uncle and aunt's old house, the basement was finished with a drop ceiling with 5-10 4x2 troffers with 4 F32s.  My grandparents have a partially finished basement that was recently mostly unfinished but most of the ceiling is finished. The pool table part has a stained glass fixture, the bar has 2 CFL can lights on a dimming switch (there used to be another but it got removed), the ping pong room has a 2x F40 wraparound that was retrofitted a few years ago to T-8, the bathroom has a 2x F40 wraparound with some Plant and Aquarium lamps, and the utility room has a socket with a CREE LED, and a temporary work light that has been mounted to something for a long time with some incandescent lamp.

Our current house does not have a basement. However, our old house had recessed can lights in the finished basement.