D.B. ALWAYS looks pissed - it's part of his character on the show. We actually stopped watching Bones a couple of years ago - it just got to be too much of a "one note, one joke" show. (She's a socially retarded ditz, he's a macho badass - yeah, we get it.)
Ben, on the other hand, is a very versatile and talented actor, and I hope his career just keeps getting better and better for him. I've been a regular at his parents' comic shop in Phoenix for twenty+ years, so I've met him once or twice, and he seems like a really nice guy.