we just bought our first TT (actually we pick it up in a few days) but size was definitely a tough decision. I think the place to start (for us anyway) was our tow vehicle. Getting a new TV was not an option/consideration, so we had to get one we could pull (5000lb limit). Myself, wife, and 2 dogs (50lb huskies). We went to an RV show at a nearby convention center to get an idea, as standing and actually seeing the space makes a huge difference versus just seeing a floorplan. We decided on Coachmen Clipper 17BH. No slides, and yes its small, but we don't plan on being inside a whole lot. Dogs can sleep on the bottom bunk or on the floor, I guess we'll find out if we made the right choice!