Technically none, though a few have issues now.
NES: Seems like it can't read carts more often than it used to.
SNES: No issues; rarely used, too.
PS1: Spindle's slightly damaged, but works; also loads slower than it used to.
PS2: No issues; soon to be 2 years old, so it'd better not have any.
Wii: No issues; soon to be 1 year old, so again, better not have issues.
GB: Screen's scratched to hell (not my doing), has a crappy battery pack superglued to the battery casing (also not my doing), never gets used (very much my doing).
GBC: Power adapter itself is broken; otherwise, no issues.
GBA SP: Power cord port is getting loose, meaning I have to jar it to get it to charge sometimes; also, 1 dead pixel.
DS Lite: Original power adapter died; otherwise, no issues.
PSP: No issues (amazingly enough, given the horror stories of the PSP-1001 model, which I have).
Sky Render - Sanity is for the weak.
