Lol, is this thread for real? Come on, you cant predict that at all. Anyone who played rhapsody 5 years ago (it was not a very popular game, its mediocre at best, very short and somewhat annoying) would not be able to tell you it would reach over $100 and end up getting reprinted. Same goes for suikoden 2, valkyrie profile etc. DDR disney was always expensive, but thats because as soon as it came out, it had an immediate fanbase (DDR was getting really hot at the time) and it was a low print run title that could not be found anywhere.
If you are going to try to set aside games as an investment, do it the right way. Do not even try to bother with current gen games, go after the games that you know will retail their values well. Go after games that are good, classic games. Go after games that are the first in a series, or what will be a series. Go after original releases of games that will be popular some day (for example, factory sealed original release copies of God of war, resident evil 4 for the cube, paper mario for the cube, castlevania dawn of sorrow, perhaps mario power tennis for the cube, dragon quest 8 etc).
The games that will maintain their values the best, or increase in value, are the older gen stuff. Right now is the time to buy sealed N64 and PS1 games or mint condition N64 and PS1 stuff. Dreamcast stuff is somewhat in there, but the premium games are already pricey and probably will not increase much in value. The older it is and the better the condition, the more likely it is to retain, or gain value.