I gave the new BSG a chance when I saw his and Mary McDonnell's name on the cast. He has taken the role of Adama and made him real. This isn't a perfect man, he is one that has flaws and can at times be ruled by his feelings and emotions. His portrayal has brought fans to the show, you don't have to be a scifi fan specifically to appreciate the excellence brought to the screen every week.
I also think that the work he does outside of acting deserves note. He does a lot of work with kids from gang areas in LA. However, he doesn't go looking for a lot of press and accolades, the work appears to be it's own reward.
If you want to see how different his range can be watch American Me and Stand and Deliver. Two men on totally different ends of the spectrum but you believe that Mr. Olmos is those men.