Jeep Cherokee Toad
I am probably unusual amongst Class B owners. We have a Roadtrek Adventurous RS (Diesel Sprinter) and we pull a Jeep Cherokee. Selecting a Toad is a series of tradeoffs, but this is near optimum for us. If you just want a small run around car almost any manual transmission vehicle will work. We once used a Subaru Forester manual and it was great; just make sure you check manufacturer's requirements. If you want automatic the choices get much narrower.
We wanted automatic, and a vehicle that could haul my music gear, and pull a band trailer when it wasn't being a toad. The Trailhawk has a automatic with a transfer case that can be put in neutral.
My diesel gets 22+ mpg by itself, and 17-19 mpg pulling the jeep. Went cross country last summer, VA to WA, and across Canada, PEI NS and New England - 9000 miles in 46 days. Pulling it is no big deal. It managed the mountains pretty well, but behaves a lot like the trucks...use climbing lane, etc. I found that just leaving it on cruise control did best.
Lost of threads out there about equipping Toads, and especially brakes. (I have one for setting up Jeep). I will say regardless of size, put a decent progressive braking system on your toad. I have the Demco Stay n Play and it's performance is outstanding.