The best thing about most types of condoms is that they protect you against sexually transmitted infections (STIs), including HIV. Lambskin condoms, however, are the one type you should not rely on for STI protection—they are able to block sperm, but not infections.
Condoms take effort and commitment
You have to make sure to use them correctly, every time, no matter what, in order for them to be effective.
Cheap and easy to find
Condoms are inexpensive (and sometimes even free from clinics and bars). Plus, you can find them just about everywhere, from truck stops to supermarkets.
No prescription necessary
If you can't make it to the doctor (or don't want to), you can always use a condom.
May help your man last longer
If your man has trouble with premature ejaculation (in other words, he comes too soon) condoms may help him last longer.
Not so good if you're allergic to latex
If you're allergic to latex, you'll need to use a plastic or lambskin condom (but don't forget that lambskin condoms aren't good for STI protection), or try another method.