[BG]

1. When copying ps2 games, what do you burn it to (media)? I have a hp dvdr2001 burner, as well as a Cd burner. Do I burn to DVD or to CD, and how do I know what to choose.

If you are backing a game up from a original it is very easy to decide what media... If the original game is a dvd based game, you put it on a dvd-r... If the original is a cd based game, you put it on a cd-r... Look on the disc itself or on the back of the game case, it will say either "compact disc (cd based) or dvd-rom (dvd based)... That is how you will know which to choose...

2. When I downloaded Mortal Kombat, I got a bin and cue file. I burned it to a CDR but Im not sure if it works or not. Should I have used a DVD instead? I opened it in my PC, and it looks like it worked, but of course I cant play it on my pc.

1st thing is you shouldn't (in my opinion) download games... You never know what you are getting... Just like the game you downloaded, Mortal Kombat, its a dvd based game and you burned it to cd-r which means you probably got a dvd-rip...
Alot of mod chips, don't like dvd-rips... Its always better to burn 1:1 ie.. cd game-cd-r dvd game-dvd-r....

3. Are all PS2 games DVD? And if not, how does it matter if I burn to CDR or DVDR?

I answered this in the first question. No, not all PS2 games are dvd games...

Another thing, you should use Clone CD to backup your cd based games, and RecordNow Max or Primo DVD to backup your dvd based games...