There are sequels that are widely considered better than the originals: The Dark Knight, Terminator 2, Half-Life 2, etc.

Then there are sequels that surpass their predecessors so utterly that they are the better-known releases solely in their own right, completely independent of being sequels at all: The Wrath of Khan, Super Metroid, Huckleberry Finn, etc.

Then there are sequels that effectively make their precursors entirely obsolete; these exist mainly within the realm of gaming rather than film: GTA 3, SSB Melee, Red Dead Redemption, etc.

Then there's Team Fortress 2, which eclipses the original so absolutely that for the longest time, the basic term "Team Fortress" on TV Tropes was a redirect to its own sequel.