Since this thread will probably last a while. Let me clear things up:
There are no recognized caucuses in the DSA, only informal ones. The only real one that's existed before the DSA boom was the Left Caucus. Some slates (like Momentum) are proposing official recognition of specific tendencies and caucuses in the DSA.
There are two main slates running for DSA's National Political Committee (NPC) which is 16 members.
Momentum: Lots of Jacobin editors. All candidates are members of the Left Caucus and self identified Marxists. They were the front runners and automatically the ones to beat. Holla Forums isn't a monolith but IMO they should be Holla Forums's #1 choice.
Twitter: twitter.com/dsa_momentum?lang=en
Website: dsamomentum.org
Praxis: Gaining a lot of attention for their support of police abolition and prison abolition. They have a Jacobin editor (R.L Stephens) who is sort of taking a strong lead here. He is an anti-intersectional marxist, but the slate avoids large political questions (like the Democratic Party) and focuses a LOT on DSA making a big impact but not necessarily on any party discipline.
Platform: dsapraxis.org
It's hard to say if one is more to the left than the other. My vote would be for Momentum. It's possible neither slate gets all their members on, though. Either way, the NPC is going to the Left after this convention.
There is also the DSA Unity through diversity program. It isn't a slate, but it is just a proposal to make DSA more diverse, even at the expense of more liberalism and colluding with the Democratic party.
dsaunity.org
The architect of this statement, a longtime DSA member and gay rights activist is also running for NPC on no slate.
riddiough.org/NPC/
The Spring Platform is also similar to DSA unity through diversity. It is a proposal, not an NPC slate.
dsaspringplatform.org
Finally, there are several lone people running for NPC. One of the most prominent is Joseph Schwartz. He is a serious lefty but is ok with using the Dem ballot line to further socialism. He has a lot of influence in the org. He is running for re-election here. Both DSA praxis and Momentum have endorsed his run.
Full list of people running for NPC can be found here: dsaconvention.org/npc/
Live stream can be found here: dsausa.org/live
What should be required reading before this convention:
jacobinmag.com/2017/08/socialist-left-democratic-socialists-america-dsa
If you have any other DSA questions ask and I will answer.