Mine is everyone's favorite genius playboy billionaire philanthropist Tony Stark:
I also love Captain America, and Black Panther and Spider-Man are also cool.
I also love Darth Vader, but the prequels put him further down for me, it ruined his cool character by making him whiny. But in the original series, his voice is cool, his costume is awesome, and his breathing filtration system thing is awesome.
A funny and serious movie character at the same time with wiity patter and hilarious slapstick moments. Despite this he always gets the upperhand anyhow.