FD, SV, Greenhill are our obvious CPs. Castle if it's legal (amazing Ike stage). Dreamland and Stadium are good as well.
I think our worst stages are Skyloft, Island, Battlefield, and Warioware. I like the smaller platforms where Ike's sword can cover a larger percentage of their rolling room.
Dreamland, Stadium 2, or Fountain is usually what you will strike to (some Foxes like the platform layout of Dreamland). I like Fountain over Story because of the less-intrusive platforms and superior recovery options.
It's player preference as Ike really doesn't have bad stages. I like the big open stages and stages with small platforms (Fountain, Lylat). I ban Island and Skyloft because of the lower ceiling and the big platforms. Stadium 2 has a low ceiling but has great platforms for Ike, this is generally where my game 1 starts every set.
I could be wrong and small stages could be the way to go. It's easier to 0-death Fox on these stages, but I think Fox benefits more because of early up airs and up smashes. Ike has a lot more KO setups at high %'s and does a better job of surviving overall which is why I pick big stages. Additionally, gimps on big stages affect the match a lot more than on small stages. Keep this in mind as both characters can gimp each other pretty hard - this depends on which player is the better gimper.
Traditionally, sword characters like smaller stages for stage control and lack of mobility. Ike isn't the most mobile either, but quick draw gives us some reason to pick stages with room to run.