I pretty much always play random so I don't really have a set style, but my terran and protoss decisions are usually pretty predictable.
As terran, I almost always go with a marine marauder medivac ball, or marine medivac and tanks. I really love hellions and they are a great way to harass early, but I am not good enough at multitasking to properly mirco them and keep up my macro, so they usually end up being a waste.
Protoss I go either a 4 gate or a 3 gate robo. Not really original, but it works and I usually end up dying if I try to go air.
When I play zerg, I just improvise. Pretty much the only consistencies in my play styles as zerg is that I like a fast expand, I really like a lot of speedlings in the early game, because I dont feel safe without them, and I almost always get infestors later on because infestors are amazing.