Players Guides, specifically RPG guides since they are typically very useful.
Statues and Action Figures: This is very expensive to get into lol
Soundtracks: I LOVE VIDEO GAME MUSIC! At least for official soundtracks, this can be expensive as well.
Pokemon Plushes: This is mostly one my GF works on, but we have around 50
original video game artwork: Have bought some really sweet original artwork from devientart users and at Anime Conventions.