Hmm...hard to choose. I have to go with multiple names.
So, I'd say Leo Di Caprio and Johnny Depp from the obvious ones. They are just amazing. Now as for the less known but still famous actors, Andy Garcia and Jamie Foxx are pretty great.
As for the relatively unknown ones, I'd say Andrew Scott...definitely (if you know what I mean ).
I like a good comedy, so my favorite actors are comedians.
Rowan Atkinson, Edie Murphy and Jackie Chan, but also many of Serbian actors who I watched through my early childhood such as Miodrag Petrovic Thistle, Danilo Bata Stojkovic and Velibor Bata Zivojinovic.
Jackie Chan, not for his acting talent but for the entertainment his movies bring.
I've seen pretty much all his movies and I like them all, even back when he was really young. I can't remember the title but he fought using the snake technique or something like that, it was like 100 years ago.