Type of lube
Virtually all lubes on the market today fall into one of three categories:
2- Silicone-based; and,
Each of these has their advantages and disadvantages. For most situations though, water-based lubes are by far the most popular.
Water-based lubes are just that: water-based. Their main feature is that they're smooth and slick, but not sticky and messy like silicone and oil-based lubes can be.
Since they're water-soluble, skin and mucous membranes will absorb them. This makes cleanup a breeze: just a little warm water, maybe some soap, and the lube will easily wash off the skin. (And the sheets)
However, it also means that you might have to periodically reapply it, depending on how long you have sex for. This is one of the chief drawbacks of water-based lube, since we all know that in the heat of the moment, an interruption is probably the worst thing that could happen.
Water-based lubes also have the added advantage of being completely condom-compatible (oil-based lubes corrode latex and cannot be used with condoms -- more on that later). One thing to watch out for, however, is that many water-based lubes contain glycerin, which can promote infections in women pretty easily. So make sure your girl cleans up right away after using one.
Popular water-based lubes include:
Astroglide: Maybe the most popular water-based lube out there. It's on the thin side, but nice and slick, and long-lasting. It's also available in many drugstores, which is convenient. If you've never used lube and are just looking to try something out, Astroglide is a great place to start.
Maximus: This is some heavy-duty stuff. Very long-lasting and very thick, this is the lube you'd use if you needed, well, maximum slipperiness. For this reason, it's popular for anal sex. Maximus is what you want to use if you really need to grease up good.
More water-based lubes, silicon-based lubes, and an oil-based lube designed solely for masturbation.
O'My: If you're a health nut, this is a great lube for you: it's completely organic, but doesn't sacrifice functionality. If you're worried about all the chemicals in other lubes, O'My's the way to go. Overall, it's similar to Astroglide.
Wet: This one is almost as popular as Astroglide, but Wet is a bit thicker. It's also available in various flavors -- perfect for when you need some added slickness for oral sex.
Slippery Stuff Gel: According to the rumor mill, Slippery Stuff was originally designed to help divers get in and out of tight wetsuits. Somewhere down the line, though, someone discovered that there was a far more interesting use for this wonderful lube. It's thick and very long-lasting, but gets somewhat stringy as it dries. Slippery Stuff Gel is, overall, a pretty good middle-ground between Astroglide and Maximus.
KY Jelly: The world's most famous water-based lube, KY frankly isn't the best. It dries up quicker than better-quality lubes, and gets tacky as it dries. I do not recommend it. KY, actually, was designed for medical use. That is, it's designed to facilitate easy entry, and clean up quickly. I suggest that you stick to lubes that are designed for sex.
Silicone-based lubes are similar to water-based lubes, but are generally much greasier and last much longer, despite having a thinner texture. In fact, that's their main advantage: silicone-based lubes take ages to dry out. No muss, no fuss, no need to reapply.
What's more; you can actually use them in water and they'll still work. They're not quite as easy to clean up as water-based lubes, though. Those who don't like silicone-based lubes say that using them is like having motor oil slathered on your bits. Others swear by it.
Popular silicon-based lubes include:
Wet Platinum: By the makers of Wet, naturally, this is high quality and very long-lasting.
Eros Bodyglide: It's almost identical to Wet Platinum, but more expensive.
ID Millennium: ID Millennium is a good lube, but not quite as smooth as Eros or Wet Platinum. It's still a good choice, however.
Oil-based lubes are... well, you just shouldn't use them. Why? First, they corrode latex, so you can't use them with condoms. Second, they're bad for your woman's vaginal health in a variety of ways. And finally, they're slimy and messy. Seriously. Baby oil, Vaseline, Crisco, Massage Oil, etc., are known for their lubricating properties, but using them is just a bad idea. However, there is one oil-based lube that I can let slide.
Men's Cream: This is an oil-based lube that I think deserves special mention. Why? It's probably the first product ever designed specifically as a lube for male masturbation. Say goodbye to weird scented hand lotion and all that garbage. If you're of the millions of guys out there who needs something to make his solo flights nice and smooth, I highly recommend Men's Cream. Just don't use it for penetration.
Slippery When Lubed
Most sex stores will carry at least a few of the brands mentioned here. There are also many online sex stores that will carry these lubes and more. Also, Astroglide, as previously mentioned, can be found in many drugstores.
Lubes can also help prolong lovemaking sessions, make your own masturbation sessions better. It's also required for anal sex -- an activity that's becoming increasingly common among couples.