Once you ask a question like this you will probably get contradictory answers. For example, I knew two girls on the same birth control regimen; one lost weight and the other gained like, 30 lbs! So it really depends on YOU.
But I'll throw in my two cents, anyway;
Ortho-Tricyclen was the first pill I was on. It gave me acne initially, but it cleared after the fourth month. I gained weight, had breast tenderness, and became extremely depressed. It also made me extremely nauseated.
Diane-35 kept me clear, but the hormones were still making me nutty. I was switched to Alesse, which made me get cystic acne (yuck).
Now I'm on Yasmin. Really nice birth control. No weight gain, maybe a change in appetite but I can still fit into my clothes. It's cleared up my acne wonderfully after three months (haven't gotten a pimple in 2 weeks. Amazing). Makes me moody, but the acne clear-up is worth it. I'm happier than I ever was w/ acne. And that's about it.
I have been on all three pills.