Some of the responses in this thread seem a bit strange. Missionary with the woman's legs up (which I have heard described as the "jackhammer" position) is one which is probably best avoided by guys who are long as it results in very deep penetration.
Doggy style is often uncomfortable for a woman if she is having sex with a longer guy as well.
As has been said, woman on top, is often best when a guy is either longer or thicker, as the woman can adjust the pace of entry and depth of penetration.
Having her pee after sex to avoid UTIs is a very good tip for guys who are girthy. Also, in this instance it is sometimes best to just not fuck for as long. After all, tomorrow is another day!
Some women feel no pain while in the throes of passion, but are sore afterward. Sometimes it pays to use lube even when you don't "need" it.
For a guy who is longer, reverse cowgirl can provide some of the same benefits and visual treats as doggy style, but the woman can limit the depth of penetration better. Spooning is also good, because most of the time a portion of the penis doesn't reach to enter the vagina, so penetration isn't as deep.