3on3 half court set since most of the time pick up 5on5 full court games end up being run and gun chuckfests, which sucks hard since I mainly operate in the post. So most of the time you just run up and down the court, give your best on D to get the possession, trail and watch guys pull a wannabe-Kobe only to get back to D getting the same idiot the ball again to chuck up another miss.
On 3on3 you have to play halfcourt sets, it's not as crowded as 4on4 and not as open as 2on2.
I hate 1on1 it gets repetetive after the very first points. Most of the times I play 1on1 to 7, because either it's onesided, so no use to carry on or it goes to 11 to 21 anyway.
I love 1-on-1, but 3-on-3 half-court is by far the best pick-up mode.
It has the most even and best talent available and encourages the best style of play.
Floor spacing is a big issue in pick-up, so 5-on-5 can become one-dimensional. With 3-on-3, picks are the most useful, players chuck the least, and passing is done more.
I like full-court and have a lot of success as a point guard in it, but it is only fun if there are a lot of good players available. There's nothing worse than continually getting crowded off-the-dribble every time and passing to people that can't finish the play. How people can't consistently knock down open 15+ footers is beyond me.
5 on 5 is my favorite, then I believe it's 4 on 4, 3 on 3, 2 on 2, then 1 on 1.
I'm a huge fan of 5 on 5 simply because I like to get out and run. If there's solid competition, I'll be able to work hard and improve my game. If the competition is lax, I'll still work hard and try to run past and through my opponents as quickly as possible.
I also like 4 on 4, but full court. I have come across people in the past who scoffed at the notion of 4 on 4 full court, but I don't find it a lot different than 5 on 5. In fact, things tend to open up a little more when playing 4's, so it brings about more running opportunities, which I enjoy.
I listed 1 on 1 as my least favorite, but it's likely my 2nd most common form of playing. It's a great workout if you want it to be, so I enjoy that aspect of it, but I miss not having the ability to work off the ball. Again though, it's actually a good mode for developing a few aspects of your game.
3 on 3 half court is the best. You have the room to work on skills better. Everyone is into the game more.
5 on 5 is cool. I like to run the floor. But in this setting, you get players who want to play 5 on 5 but end up with 3 on 5. Not everyone is playing defense or running back on offense. Folks get lazy.