Mirena
"I have had the Mirena for a total of 10  years & I'm very pleased. The only part I don't like is the insertion process (yes, it can hurt, but it's a quick pain if you have a doctor that knows what they are doing), the bacterial vaginosis I sometimes get & the ovarian cysts. Everything else is great! I rarely have periods & when I do I just spot a little (I used to have very heavy periods & BAD cramps). I also haven't ended up pregnant. I highly recommend this form of birth control."