In the late game, I find that battleships with lance/artillery/artillery can punch through anything
If I keep the comp pure, awakened empires or crisis fleets can pick off 2/3 battleshipsein an engagement, so I take 5 each of cruisers and destroyers as sacrifices, filling the rest of my fleet cap with battleships and titans. I take care not to have two titans with the same aura in a fleet, but I tend to pile a lot of titans into one primary fleet.
Corvettes are for pirate patrolling, and even that becomes obsolete once I've built a gateway trade network. Every now and then I see folks claiming that evasion focused corvette swarms can be powerful, but I've yet to try it myself.
Corvettes are best bang for buck but you'll take losses. They are especially good vs the Gray Tempest.