Again, thanks for the info, I'm still a rookie into Ys stuff so I didn't knew that the ps2 versions where considered "bad".
I've seen the snes versions and ys iv for the turbografx and the look awesome, not to mention the incredible work some guys did to translate iv for the turbografx, so maybe I should get my hands on a snes/turbografx and play them.
Also Ys: Memories of Celceta look pretty awesome aswel, I should totally get that to my psp.
If you are going to play Dawn of Ys there is a few things you need to keep in mind:
First, that it is specifically a sequel to the Turbografx/PC-engine version of Ys I+II. Because of changes done both to the Turbografx version and to the Windows versions there are going to be some inconsistencies with the plot of the version you played. Although the only one major enough for me to remember was the fate of the Sara (you'll be told what happened to her early in Dawn).
Secondly, Dawn goes to great lengths to tie the Ys IV and Ys I+II backstories together. Some of the ways it does this probably contradicts what is currently canon and what happens in Origins. Memories of Celceta meanwhile takes the complete opposite approach and removes all Ys I+II elements except for Adol being the main character. The SNES game (from what I've heard, haven't played that one) takes something of a middle-ground, which I think was the original intention.
(Oh, and note that Memories of Celceta is for the PSVita and not the original PSP.)