I'm on Marvelon... have been for about 5 or 6 years. No side effects except my cramps are tremendously better, it cleared up my skin (no more PMS monster pimples), and my periods are much lighter and shorter now.
I switched once for about 9 months cause my doctor said that I shouldn't be getting cramps at all (I was still getting slight ones, not complaining, she asked) and I wanted my boobs to grow. So I took Tricyclen (I think it was called... it had a sunflower on the package, and for some reason I thought the name started with a "D"). My periods were heavier and lasted all of 7 days, and I had severe cramps for the first 3 - 4 days. Stupid doctor.
I also went off the pill for almost a year... and I HATED it. It took me almost 2 months to first get my period after stopping the pill (weeks of torture), my cramps were back to being severe and unbearable, I got noticeable PMS, I never knew when my periods were going to start, sometimes I got them twice in a month, they lasted a full 7 days and were heavier.
I'm so happy with the pill that I think I take it for granted. I know exactly when I'm going to get my period, when the cramps will start (so I can take a pre-emptive Motrin and barely feel them), how I will feel throughout the whole cycle, and when my period will stop. And I can choose to skip all that if I want to by taking two packs back to back!
Also, with mine, according to my doctor, it's not really important to take it at the same time everyday... she even said that I'd be fine if I forgot a day and caught up by taking two at once. Which means that I generally try to take mine before bed (anywhere from 10pm - 6am) and if I forget, I just take it as soon as I remember.
I <3 my bcp. haha