PCSX2 is the best and it is still in the beta stage. The related links will answer the second part of your question better. The Emulator tries to make your PC a PS2 and it never works as well as a PS2 and many titles are not even playable. Playable titles are not without there problems and personally it does not appear worth the trouble
see both the related links for information on the best working PS2 emulator.
PCSX2 is the only PS2 emulator to consider and they are working on Version 9.9
No the emulator does not work with the PS2, it uses the PS2 Bios
The best PS2 emulator in terms of compatibility and relative speed is PCSX2.
just downloading a ps2 emulator and download a ps2 game to order to play the game. It is not anywhere near this simple nor does any PS2 emulator work except in a beta or test version. The best rated emulator is the PCSX2 and it does not even allow you to start many PS2 titles. After the PSCx2 is downloaded it needs someone with real computer skills to start the set up process after you locate a copy of the PS2 bios.
No the Xbox could not run an emulator for the PS2
No, a DS emulator is not compatible with the PS2
pscx 2 is still the best ps2 emulator out there, and it requires a very strong system cpu/ram/gpu. Emulating a ps2 is a heavy task, so any ps2 emulator will need a high end system. My suggestion is try and find the best GPU pluging.
PCsx2 is the best emulator although it is still in beta stage and it is also free. see related link
There are no PS3 emulators and the bios file for the PS3 would not work in a PS2 emulator
no The PS2 emulator works on very few games and does not include the PS2 Bio which you would also have to download from somewhere. In theory the system would work as you want, but it never has.
If it is a copied game it will work only on a chipped ps2(the chip reads copy games)if it is a normal ps2 game it will work.