Well, I like the Endor/Trench Coat Han.
However, as a kid I wanted the Carbonite Han for a LONG time. I still remember how happy I was when my parents bought him for me. I also remember how hard he was to find back THEN.
Anyway, when I got back into collecting the vintage stuff, he was one of the first figures I had to get. So he remains my favorite.
Besides, I always felt like you get 2 Hans with the Carbon Freeze Han...one regular and one frozen block Han...hehehehe