I thought i would make a list of video game consoles that can be emulated with common hardware, without requiring any extra dumping work other than the games themselves.
Here's the list of consoles that can be emulated without a BIOS copy, with simply a CD/DVD drive.
Sony Playstation 1 (with HLE bios emulation. psx4all, epsxe, pcsx-remarmed and its derivatives... all have this option. Limited Compatibility)
Sega Saturn (Yabause forks have an HLE bios emulation option. Limited Compatibility)
Sony Playstation 2 (Play! is the only PS2 emulator with HLE bios emulation. Very early stages though unfortunately)
These consoles can be emulated without a copy of the BIOS but have very poor emulators.
NUON (Nuance's author died and the emulator is Windows only. Source code was made available but copyright status is unclear)
Jaguar CD (Project Tempest can run homebrew games and some commercial games. Windows only and proprietary)
PC-FX (Only with Magic Engine FX and Windows only, also paid. Mednafen requires a copy of the BIOS.)
Only works under some instances but HLE bios emulation is still available.
Redream (The open source release has HLE bios emulation. However, only homebrew games can be dumped with a common drive)
Can be dumped without any special trickery but no emulators are available
Tandy Video Information System (Windows based ?)
Bandai Pippin (would probably require a copy of System 7.6 anyway)
Can be dumped easily but requires a copy of the BIOS
3DO (requires a copy of one of the models. No work towards HLE bios)
Amiga CD32/CDTV (requires a copy of the kickstart. An open source one is available but cannot boot CD games from what i gather)
Neo Geo CD (All emulators for it requires a copy of the neo geo bios in addition to the CD one)
Sega CD (requires a copy of the BIOS. In addition, it is also region locked)
PC Engine CD (requires copy of the syscards. Game Express made their own but it is still proprietary)
Philips CD-i (requires copy of the BIOS)
No copy of the BIOS required but can be painful to dump
Gamecube/Wii (some drives can dump those games but most can't. An original console is best)
Sony PSP (no UMD drives in the wild. Requires a CFW and a PSP to dump those games. Digital only games however requires no such things and PPSSPP can run them happily)
Xbox original/360 (Requires either a hacked drive or the original console)
GB/GBC/GBA (Requires a Retrode)
NES/SNES/N64/Virtual Boy (Requires a Retrode)
Master System/Megadrive (Requires a Retrode)
Atari 2600/5200/7800 (Requires retrode)
CBS colecovision (Arduino adapter)
Requires BIOS/firmware and a special drive or console
Sony PS3 (Can only be dumped with some drives. Tools are proprietary. Firmware is copyright Sony)