Snoke's ship.

If there's a ship raid, I can't imagine they'd start with anything other than one of the death stars, being as they are the most iconic piece of machinery in the franchise. If they wanted a two stage option (phase 1 and/or 2 toons/land battle, phase 3/4 ships), which is probably likely given the limited number of options we still have for ships, then I'd bet on Death Star II as it is (a) a Death Star and (b) can involve a land-based battle to take down the shield generator.

In fact, it gives a lot of options for how they want to structure it. Phase 1 (and/or 2) could be ships, taking out the executor because they can't attack the death star yet. Phase 2 (and/or 3) could be land to take out the shield generator. Phase 3 and/or 4 to take out the death star. Breaking it up this way would force us not to be able to solo the entire raid with a single team, ever, because you have to switch back and forth.

Or if they want to keep them together, Phase 1 and 2 could be land, phase 3 and 4 could be space.

Lots of options, but if we have a fleet raid, and if it's not the iconic death star, I'd be very surprised. Huge marketing miss.