Heroes
1 - Crow (The Longest Journey, Dreamfall, Dreamfall Chapters) - The real hero.
2 - Nathan Drake (Uncharted series) - He made Uncharted what it is. Without his wit, the game would have been just another well polished shooter.
3 - April Ryan (The Longest Journey) - April beats out Zoe because I just remember loving her dry humour. Specifically in TLJ, that is.
4 - Sergeant Cortez (TimeSplitters series) - Action comedy hero straight outta the style used in action comedy flicks of the 90s.
5 - Zoe Castillo (Dreamfall, Dreamfall: Chapters) - Even though Crow & Zoe beat her rather notably, she's still an excellently written character. Juuust edges the honourable mentions.
Honourable mentions: Snow (FFXIII), Tifa (FFVII), Sully/Chloe/Elena (Uncharted), Trevor (GTA V), Urist (Dwarf Fortress), Ellie (The Last of Us).

Villains
1 - Shinra (Final Fantasy VII) - Might be cheating since it's a group of people rather than an individual, but Shinra was just excellently done.
2 - Vaas (Far Cry 3) - Sure, he might be a cliché to many, but to me, he was the mastering of the pyshonutter. I loved every moment.
3 - Wheatley (Portal 2) - I adored his character from start to finish.
4 - The Joker (Batman: Arkham Asylum) - Because you can't go wrong with Mark Hammil's Joker.
5 - Pagan Min (Far Cry 4) - I admit that I was struggling to think of villains at this point. Min edges out a few others on comedy value.
Honourable mentions: Sephiroth (FFVII), The Reapers (ME), Kefka (FFVI)