I go through phases of buying too. Went through an arty stage one month and bought Alice, Fantastic Planet and L'age d'or with Un chien andalou(Luis Bunuel and Salvador Dali's surrealist films). Also bought Hausu(house), Viy(the spirit of evil) Uzumaki,Come and see and The Hourglass Sanatorium. All pretty interesting and unique films.
In contrast in the next phase i bought alien films Promethius,Galaxy of terror,Evil Aliens and The Deadly Spawn.
Lately i've bought alot of sleazy and cheap but entertaining movies; Bloodsucking freaks,Take an easy ride,Mother's day,Demoniac,Blood orgy of the she devils,Skinned deep and The Child.
Its good to have a bit of variety i think.