i've seen that some people went out of their way to make CSGO models, which always look pretty cool and are usually pretty well-made
or even some small, more vanilla (to csgo) like the Phoenix model, and the cut armored suits for T and CT

so to cut to the chase, i think some CSS models would be Cool for the game, considering CSS has a interessting mix of T factions and CT u have a rather handful of options to give it a try (well aside from the phoenix mode but that depends on weather u prefer the css one or csgo one)