I’ve been building rockets for a little over 2 years now and in that time my favorite build has been the OOP 1/100 Estes Saturn IB. I bought it off a fellow club member. The whole kit fit together perfectly. It was complicated but not difficult. The detailed instructions were easy to understand. Even though the kit was 20+ years old, everything was in great shape including the decals. I kept the mistakes to a minimum, and I think it came out great. It was a very rewarding build. The rocket is built in five sections. The fin assembly, the first stage fuel tubes, the S-IVB stage, the command module and spacecraft, and the Launch escape tower. These sections are painted first, then put together. Probably the hardest part of the build, the 8 fins are vacuform like the old version of the 2157 Saturn V. You glue 16 halves together with some styrene strips in between to hold them together. They’re then glued onto the aft body assembly slightly canted. The rocket needs to spin for stability. The eight fuel tubes are painted separately, then glued to a central larger tube which is hidden from view. You then drop the fin assembly onto the tubes. It’s a little nerve wracking getting the painted tubes through the scalloped edges, but they fit just fine. All the wraps fit great and the second stage is good masking practice for the Saturn V. The transition and above is exactly like the 1/100 Saturn V. For the command module, I took the pattern available from Chris Michielssen’s blog and cut it from trim monokote. Chris’s pattern was for the Saturn V. The IB was slightly different (according to ROTW), so I made a minor adjustment. There are display nozzles that fit into the aft end. It flies on 24mm. I’ve launched it once on a D12-3 to about 400 ft. It flew nice and straight with the spin from the canted fins. No damage upon landing. And it makes a great matching set with the 1/100 Saturn V! And that is my favorite build - so far. Feel free to post your favorites here.