Favorite boss in a game

[Man 2]

Mostly because he's played by John Noble. He's a sleazy little demon in-game though.
Oh, did you mean... Oh.

[Ad Bot]

[Tetris]

Probably Oryx or GLaDOS

or Makarov or Doopliss

[TurnipBlog]

Probably the end Doom bosses (original) or the end boss of Portal 2. Not going to spoil it, just in case.

[BubbaGum]

Mostly because he's played by John Noble. He's a sleazy little demon in-game though.
Oh, did you mean... Oh.

THaT WAS SO ClEVER

[NalNalas]

I know. it looks stupid. But, This is the only picture I could find its Chaos from Sonic Adventure

[curiosblockland6]

Anyone who recognizes this is awesome. If you've ever played an R-Type game, you know the feeling of approaching a massive alien several times larger than you.

[Skull Candy]

[Yosher]

bob the killer goldfish, obviously...

[Wheatley]

or

[sir dooble]

Rootmars from Metal Slug 3.


Or Huge Hermit, also from Metal Slug 3.

[tkepahama]

The Ubermorph from Dead Space 2

[sorrel]

Rakk Hive

[Redconer]

Count Bleck from Super Paper Mario

[ArmyUnit]

In terms of design, my favorite has to be Blazin' Flizard from MegaMan Zero 3:

[Katamari007]