For Kite Surfing I own a 9M 2004 Fuel and a 13M 2004 Fuel, as well as a 16M 2002 Fuel. I have flown each of them at least once, but that is all I have flown the 16. The 9 is a workhorse in a steady 18-20 kts. It flies fast and turns quickly, definitely a solid performer. I haven't yet surfed with the 13M, but It should handle well in the 12-15 kts range for my weight. I also own a 5M Best Grunt that has seen action on Land, Snow, and Water. A Low aspect kite this stable performers is an excellent tool to learn the dynamics of LEI kites, or for those extremely Nukin (30kts sustained) days like when I bought it in Cape Hatteras. This Kite having seen many a crash, I can say that Best builds them Strong!
For Landboarding I have a few foils. A 2M Wasp Trainer is fun for warming up with, but lacks any usable pull (except under Nukin conditions). My parents graciously got me a 3.6M Ballistic Burner (I sent them the link in email). To date it has been a very reliable and powerful tool for learning to landboard (safely). However today arrived my 2005 Slingshot (Yep again) B5, all I can say is Wow! The wind was barely a steady 3kts with gusts to 5kts and the kite was flying. When the wind kicked up to 7-8kts she really came alive and started to provide usable power. I immediately jumped on the board and the wind died as suddenly as it had arrived. I have confidence that the B5 will become a well used part of my quiver. I will of course need to modify the bar setup as on my other foil with an active breaking system.
I also have a Flysurfer 12M Mastair that has only been flown twice on land. It steers like a pig compared to the LEI kites and likely will not see substantial water use, except in very light (8-10kts) wind conditions. I purchased an AirBliss 8M Hybrid foil, but this kite suffers the same steering woes as the Mastair. It requires excessive bar pressure to turn the kite. Attempts at an Active Braking system on the larger foils has not yet been successful.
For Stunt Kites I have a Quad Line Revolution III and a dual line 5ft delta wing. They rarely see much use anymore in favor of the wind engines of land and water. However countless hours on both kites has proved very useful in providing a good foundation of kite flying skills.