So I found out that PSO ep 3 gives you rare items if you have games saves for certain other games on your memory card. This got me thinking, what other games access game saves from other games to import the data, trade items across games or to unlock features? I thought it would be handy to have a complete list since it might affect the order in which I play games in the future. Here is a list of everything I could think of, but I'm sure there are a lot more. The arrows show the direction of importing and a ? means I'm not sure. No PC games please.
Baldur's Gate: Dark Alliance 2 (GCN?) <- Baldur's Gate: Dark Alliance
Harry Potter: Chamber of Secrets (GCN) <-> Harry Potter: CoS (GBA)
Phantasy Star Online Ep 3 (GCN) <- Sonic Heroes
<- Billy Hatcher
<- Sonic Mega Collection
<- PSO Ep 1&2
<- Sonic Adventure 2 Battle
<- Sonic Adventure DX
Super Smash Bros Melee (GCN) <- Pikmin
<- Metroid Prime
Champions: Return to Arms (PS2) <- Champions of Norrath
Gran Turismo 4 (PS2) <- Gran Tursimo 3
Baldur's Gate: Dark Alliance 2 (PS2) <- Baldur's Gate: Dark Alliance
Baldur's Gate: Dark Alliance 2 (XBX?) <- Baldur's Gate: Dark Alliance
Dead or Alive 2 Ultimate (XBX) <- Dead or Alive 3
Meta Gear Solid (PS1) <- Castlevania: SOTN
<- Other Konami PS1 games?
Capcom v. SNK (DC) <- SNK v. Capcom Cardfighters Clash (NGPC)
King of Fighters R2 (NGPC) <- King of Fighters Dream Match (DC)
SNK v. Capcom Match of the Millenium (NGPC) <- Capcom v. SNK (DC)
Golden Sun 2 (GBA) <- Golden Sun
Zelda: Oracle of Seasons (GBC) <-> Zelda: Oracle of Ages
Ugh, the Pokemon games would be a mess. Anybody know what the import compatibility paths are with those? Also, I know Harvest Moon has some importing or trading abilities, but the specifics are beyond me.