I play piano mostly, but considering my living space, I had to get a relatively portable and non-backbreaking keyboard, which would be the Korg SP-170.
Also, I have a smaller keyboard which I take along, it would be the M-Audio Keyrig 49, which has to be... the flimsiest there is, but with some delicate fingering and good samples, not too bad, does the trick. I also own an electric guitar, but it's a Squier Strat, don't have much love for it, but again, good enough.
Whenever I get the chance, I play various uprights, and I somewhat frequently get to play a Yamaha C3 Grand at a local hall, it's quite the luxurious occasion!