Easy Games You Loved

What are some games that you thought were super easy -- regardless of genre -- but were still really enjoyable, in your opinion? Note that I don't necessarily mean "simple" or "casual" -- just easy.

For example, unless you ramp up the difficulty with mods, Skyrim is a very easy game, Yet is still (IMO) extremely fun to play (between the exploration and sneaky-snipy madness).