I sold my old systems to help pay for the new ones, so I sold the games with them.
MegaDrive: sold it all to buy the N64
N64: sold with a game and controller... but bought my sisters N64 a week later with 3 games and a controller for less money.
2nd N64: sold about half my games shortly before I bought my GC, but I kept the N64 system.
GC: sold with 3-4 games about 6 months before I bought the Wii, kept most games though to use on the Wii
2nd N64: finally sold with the rest of the games and stuff about 2 years later, I miss Blast Corps and Pilotwings but otherwise I haven't missed it.
Wii games: I keep the games I think I am likely to want to play again, but sell ones that don't have much replay value to me.... for example I sold Super Mario Galaxy even if I think it's an awesome game, I played through it completely 2.5 times (three times with Mario, twice with Luigi) then sold it, I will probably do the same with SMG2 after I have played through it once more.
