This is my current collection.
Several DMG's here, and a pocket, have got a backlight and are prosound modded (RCA and/or 1/8"). The Game Boy Color has got a front-light taken from a broken SP. And the DSi has got the EyeCandy Clear Case.
I have two usb flash cartridges for the game boy, a Bleepbloop and an EMS 64M.
The C64 is in its original state but will get a second SID-chip soon (SID2SID). I'll be using it with the MSSIAH cartridge, the second SID-chip allows me to use six channels instead of three.
The R4 cartridge contains Nitrotracker for the DSi, it's fun to use but I prefer using my DSi just for games and LSDJ to track, though.
My NES is in original state. I don't have any plans bending it or using it for Chiptunes. Maybe if I can find a cheaper alternative for a Powerpack ill start working on it but it's too expensive to work with my NES right now. My priority is completing the C64 SID2SID project first.