In the grand scheme of things, Blane is my overall favourite. Fire-types generally are rockin', but his Magmar is just off the hook! Imagine now if he eveolved it into a Magmortar! He'd be unbeatable!
But in Sinnoh... Roark would have to be my favourite. I do like rock-type Pokemon in moderation, but his Probopass in the Battle Zone is awesome! When I use my Floatzel's Surf attack, it doesn't take it out unless it's a critical hit, and then it has Thunderbolt! It's formidable if you're a similar level to it. Plus he uses 2 different ancient Pokemon in Aerodactyl and Cranidos, which is always cool!