Army Builds?

Hey guys I've been thinking a lot about this in my head and I wanted to share it as it comes across my mind. We all have armies that we play and we all know about one thing, the builds that come from the codex of the army/armies. For my main army, codex space marines I can think of a few builds to come by which are Mass Dreadnought Armies, Drop Pod Armies, All Bike Armies, Razorspam Armies, Pod+Biker+Mech Armies, Vulkan (Sally) Armies, Termie Spam Armies, or what I play which is mainly just an MSU Mech Army. All of these builds are all fun to play. Armies that are built around them vary from person to person and they are all well known I'm sure. Some are taken often , some are not because GK, SW, BA, and IG seem to outshine CSM because they (CSM) are not played as much as the previously mentioned armies,along with xenos. I stick with with Vanilla Space Marines simply because it was the first codex I ever bought. I wanted to try them out, learn how to play them, paint them, and all that stuff with starting a new army. Guard looked cool, SW didnt appeal nor did BA (Its not like they were boring) and I picked up Black Reach and chose SM because of it. But now that I know of the many builds out there, I want YOU to see if you can come up with army builds from the codex you play that can be competitive, just fun to play, or both. I've done my part and now I'm interested in what other armies have in the current edition.