I'll cover LTT since I haven't been to Ohana in a few years.
LTT serves what I consider to be American "comfort foods", and is pretty much like what skw444 described. However, we had more of the traditional Disney characters than that. We saw, in addition to those skw444 mentioned, Mickey himself, Dale and one other character I can't recall now. LTT is quite possibly my favorite restaurant in all of WDW. If you can sit by a window, you get a great view of the Liberty Square section of MK as well.
Make sure you're at least 10-15 minutes early for your ADR. They have group seating times at LTT.