The Hardest Bosses of Video Games

The items in this list have been selected by the author of the list for you to vote and comment on.
The Top Ten
1 Solgryn - I Wanna Be The Boshy
2 Sonic - I Wanna Be The Boshy
3 Megaman - I Wanna Be The Boshy
4 Koloktos - Skyward Sword
5 Sans - Undertale Sans or Sans the Skeleton is a character in the 2015 RPG Undertale created by Toby Fox. He is a lazy, pun-loving skeleton who is a supporting protagonist in the "pacifist" and "neutral" routes of Undertale, and a heroic antagonist/final boss of the "genocide" route. He is known for his incredibly difficult boss fight, bad puns, and the phrases "geeetttt dunked on!!!" and "you're gonna have a bad time." He is also named after the font "comic sans." Known for also being Ness from the Mother series. (known as Earthbound in Western territories.)

Sans or Sans the Skeleton is a character in the 2015 RPG Undertale created by Toby Fox. He is a lazy, pun-loving skeleton who is a supporting protagonist in the "pacifist" and "neutral" routes of Undertale, and a heroic antagonist/final boss of the "genocide" route. He is known for his incredibly difficult boss fight, bad puns, and the phrases "geeet dunked on! " and "you're gonna have a bad time." He is also named after the font "comic sans." Known for also being Ness from the Mother series. (known as Earthbound in Western territories.)

6 Mike Tyson - Punch Out!
7 Tabuu - Super Smash Bros. Brawl
8 Ornstein and Smough - Dark Souls

This two are hard. I see on lists bosses from Mario an sonic, Like those games are harder than Dark Souls. O&S killed me many, many, times.

9 The Guy - I Wanna Be the Guy
10 Chef Antoine - Dead Rising 2