Any infinite range ship*, as I find carting around scout starships or cloaker starships around with my fleet and trying to keep them close not very fun.
However, that is only for an initial unlock. If they get it later on in the game, I'm fine with it, as at that point, my economy is strong enough to not mind a few losses from somewhat loose macro.
Yes, lots of other ships are somewhat annoying in AI hands, but none of them (except the one class mentioned above) enough so to make me "rage quit" and reroll. Every single ship has a counter that is available at all times, though admittedly, some have counters that require more micro than I really find fun.
*and tackle drone launchers and Spire blade spawners don't count for this. They have a ridiculously huge effective range, but not infinite.