Anytime you have the choice of buying all four, then buy them, theyre all good games. But if you only pick one, DEFINETLY choose skies of arcadia. That game is one of the greatest rpgs ive ever played, itll easily keep you busy for 40+ hours. If you are even remotely interested in rpgs, then pick that up, you wont be dissapointed. If i had to choose a second, it would be splinter cell btw.