This here gave me the idea.
At the moment, there are 61 plush and 2 statues, how about adding 7 trophys you get by completing your Pokedex? One for each Generation and one for all Delta PKMN.
Something like adding a DexGuy (like the FlagGuy) that rates your Pokédex, who gives you one trophy every time you have all Pokemon that where added in a specific generation (DexNr 1-151 for Gen I; 152-251 for Gen II; etc.)