It will be better if we make a whole game out of best components. Hitman series:
Codename 47 - soundtrack, story
Silent Assassin - missions, the way anaesthetic works
Contracts - difficulty (SA too tough, BM too forgiving), some missions
Blood Money - mechanics / technical advancement
Pokemon series:
R/B - freedom / lack of handholding, attack sounds, hyper beam mechanics, amount of optional places to explore (Power Plant, Cerluean Cave, Seafoam Islands - all with legendaries in them)
Yellow - difficulty (due to starter choice - requires a full team instead of one OP starter)
G/S/C - the rival, two regions, roaming legends and other hidden pokemon (Lapras etc), kurt's balls, day / night system
R/S - region, pokemon designs, contests
Emerald - battle frontier
HG / SS - gym leader difficulty / teams, rival's backstory, pokeathlon
D / P - no redeeming qualities
B / W - story, pokemon policy (no old pokemon to catch)
OR / AS - soundtrack
US / UM - no redeeming qualities