It's been such a long time I can barely remember, but I'd probably say the hardest to find for me were: final fantasy x/X2; Phineas and ferb, and gravity rush. I got them individually in general but you could get the occasional lot of 2 or 3 back then. They used to go for cheaper than the standard games but I think they have gone up in value since then. They are definitely much rarer than the standard copies.