Vaginal is always easier, and of course tons of fun! But I love anal. Really really love it, nothing makes me nearly as wet as a bit of anal stimulation. So I really think both are great! Just depends on the situation.
I think I like vaginal sex more with a partner but during masturbation I think I definitely get more pleasure from anal stimulation. Anal stimulation just tends to make my orgasms significantly more intense.
I prefer vaginal, but like anal too. Too bad my partner isn't interested in it, but I'll gladly take him wanting vaginal and not anal over the other way around.