Hey, so long as there's people showing off their mad guitar collections, why not a keyboard thread? I'd extend this to any sort of piano-based instrument including pianos, keyboards, organs, keytars, melodicas... hell even accordions.
I'll start:
1. Magnus 15-key Electric Chord Organ, don't know date but has to be from the seventies or earlier. I got this for $5 at a yard sale, I'm pretty sure it's supposed to be a toy. It was broken when I turned it on (organ keys stuck) but I took it apart and cleaned it out and now it works mostly okay, though when you depress the keys they tend to stay depressed until you manually click them back up. I really love playing around with this thing. It sounds like a church organ and when several of the keys are depressed there's a real wall of sound. I love this thing.
2. Casio SA-75 Starter Keyboard -- It's cheap, it's small, I can hold it in one hand. I haven't played this as much as I thought I would (it was a replacement for a full-scale, professional keyboard that I sold to my mom so she could give it to my sister who never plays anymore anyway), the keys are really tiny, even for a girl's hands. I think it's mostly for kids. I will be trading up soon.
3. Hohner 32-key Student Melodica, I bought this after seeing a band that incorporated the melodica, it's pretty awesome to play though I can't sing while I play it. Love the accordion-type sound. Love pulling it out to play around people who've never seen one before. Keys are full-sized even though it's a "student" model.
Unlike the guitar/bass, at which I am still basic/intermediate in skill, I took piano lessons when I was a kid so am pretty good at banging out tunes when I want to. I'd like to get a better, larger chord organ someday as I am having a lot of fun with my little play one and it would give my music that lo-fi gothic Americana edge.