Toss up between my Estes Big Daddy or my Vaughn Brother's Rocketry Stretch Blobbo. I like the Big Daddy because I beefed it up and fly it on D12's up to F39's. The Blobbo takes anything I toss at it, including chad staging.
My modified Comanche-3, D12's on the first and second stage, E9 on the
third stage. Have not had the opp. to launch it with all 3 stages yet. need
a bigger field. Did get it up on 2 on a very calm day, lost sight of it but hear
the ejection. I came down just a few hundred feet from the pad.
Thrustline Duster, it flies great from C11s all the way up to F39s
I even upscaled one for my L1 bird
I am a big fan of John Rowan-Stern's designs. Even though many of them are simple 3 & 4FNC they all seem to have the right size/scale/balance/line... whatever combination of things that give a rocket the right "look" At least in my eye
Close second would be the Arapahoe E (Don't have one built at the moment) and the Mighty Mick. I've also got an Astral Lance kit, but I've never even seen one flown before
My choice changes after every launch I attend. Right now it's a 3-way tie between my Nova, my Orbit and my Echo-1 (cloned FSI models built with parts from Semroc). I have built quite a few rockets with 24mm mounts and I have many more in unbuilt kits, but I have only launched a handful of them so far due to space restrictions. None of them have had more than 2 or 3 flights, either. Because of that I haven't really settled on a single favorite 24mm rocket yet.
A copy of a scratch built over on EMRR called the Flat Black by Larry Brand. A tube fin rocket that flies on anything from a C6-5 to a E15-7. I've never had anything but straight-stable flights with this rocket. When the wind kicks up this is the rocket I reach for.
i have to say it is an estes stormcaster. never had a bad launch on it. works great on D12s. high and straight. i did crack a fin once but a little super glue and it has lasted many flights. did 2 launches with it today and they were about a perfect as it gets. if i remember correctly, rocksim shows about 750 - 800 feet on a D12.
2nd choice would be a big daddy but it really needs a bit more powerful engine. the d12s work nice but would like a little more ummph and altitude.