Spore and GTA4...
Spore has some amazing technology inside it that is enough alone to make it a good toy, the game itself is dreadful though. I was massively disappointed with how dumbed down it had become, clearly in order to sell to the general casual audience who have no major love for RTS, Sim or RPGs, but would gladly accept any mediocre crap thrown at them.
With GTA4, during the time I played it I really enjoyed it, but once the story is over, is there REALLY any fun in trying to find 200 pidgeons, increase the pointless relationship with your 5 buddies, and find all hidden ramps? It doesn't really feel like a game for the most part, more just like a very cool interactive movie with A LOT of driving and some stupidly easy action sequences. It all looks very nice, but where's the GAME? It's more like an extremely dull, city-shaped sandbox, only it's not really filled with sand, it's filled with pebbles that just hurt your fingers when you move them around.