The only synchro archetype I think I've used is Blackwings which are extremely fun in my opinion, they're also good for spamming rank 4's which is always good. I do however have a buster blader deck that's mostly synchro centric getting out king calamity is always fun it literally stops your opponent from playing, there is also a LOT of red dragon archfiend support including the recently announced red rising dragon which can get out abyss fairly easily or you could probably try and make a quasar deck, that's something I've always wanted to do but I have no idea where to start except the obvious quick synchron, level eater, junk warrior, formula synchron etc.