If it is one thing I feel is a great thing modern medicine affords us, it's the ability to control by artificial means if/when someone gets pregnant. With all the effective forms of birth control out there, there's no reason you should be getting pregnant (or impregnating a woman) if you are smart about what contraception you use, and you use a variety of methods of contraception.
That said, there are drawbacks to certain forms of contraception, most notably hormonal birth control. Raging hormones, PCOS, increased risk of cancer and heart attack, and the list literally goes on and on. For this reason, it's not a wise choice for couples who are done having children or just don't want children at all. Further, so-called "Natural Family Planning" has a ridiculously high failure rate (sorry Catholics, but don't tout how NFP is so effective, because the bottom line is that it's not), and as such is not reliable either. Of course, the main fallacy with NFP is that the woman is only fertile for such a time period, which is simply not true. You can get pregnant at any time (even during your cycle), so don't buy into that garbage.
So, when it comes to those couples who are finished having children, couples who don't want children, or people like me that are repulsed by the idea of having children, this message is for the men. It's time for you to step up to the plate and get the "big V." It's safe, a lot easier on you than sterilization in your partner, and is foolproof (1/1000 failure rate usually caused by going off other forms of contraception too soon. Failure after three months is unheard of). Recovery is fast with minimal post-op pain. I know from experience - I had one done this year (23 years of age, no kids), and I do not regret it. I can't stand children, don't want any.
It's really on us to take one for our partners, guys. Suck it up, be a man, and get snipped. Your partner will thank you for it, and your sex life will be just as great as it was pre-vasectomy. It's much easier for you, so just do it.