You will note a lot of threads on this topic.
The basic paints are two part polyurethanes, one part polyurethanes and enamel.
The two part paints provide the hardest and most durable surfaces but are the most difficult to work with. Ideally a sprayed application is used and produces the best results. As someone who has worked with paints you will realize that spraying 2 part (and probably one part) paints requires a forced air respirator. These paints can also be applied with the roll and tip method (roll with foam brush and knock the heads off the bubbles by lightly dragging a foam brush over the surface). Typical brands of this type are Interlux Perfection (formerly Interthane), US Paints Awlgrip, Imron, etc...
One part paints such as Interluc Brightsides are slightly less durable than two part paints but produce a nice finish and are more easily applied - usually with roll an tip method. These tend to have very good flow characteristics.
Enamel paints I have not used but are the least abrasion resistent of the three types and are the least costly.
For painting decks typically a less shiny paint is desired and you can use any of the above paints but with a non skid additive mixed in. Typically silica or sand. I have used Brightsiodes and the Two Part paints with non skid additive and a flattening agent. Interlux now sells a product called Interdeck which is basically Brightsides with the non skid additive and flattening agent already mixed in. Non skid paints such as this are typically rolled on with a foam roller.
Check out the web site below my signature and look at the LASER RESTORATION link to see this painting done on a very very old Laser.
Hope this helps.