I'm sure this has been asked before, but a quick search didn't turn up anything.
I know some people buy enough ships to be able to fly any possible 100 point squad, but having 6 HWK-290s, 4 TIE Advanced or 4 Shuttles seems pointless because you're never going to use all those ships except, perhaps, for the novelty.
In your opinion, what is the maximum number of ships of each type that can actually be useful in effective, non-gimmicky 100 point lists?