Which car should I buy next?

You might check into the Ford Escape hybrid if MPG is really a concern with A/4WD.
I test drove one a couple years ago and it made it to my final 3 choices when I was looking to buy.

I think one or two regulars on here own one, or drive one regularly(their work’s fleet vehicle)

The Legacy sedan seems smaller because the Outback suspension has been raised up and the roof is taller. But basically they’re the same. I didn’t like older Imprezas, but the current one seems much nicer. They don’t make a wagon. The hatchback is a practical size. I’d also suggest the Mazda CX5. It’s maybe a hair smaller than a CR-V or Escape, but bigger isn’t necessarily better. The Mazda gets excellent gas mileage, with either engine, though most (even Consumer Reports) think it’s a little underpowered with the smaller engine. Definitely I’d gt the larger engine if I were opting for awd.

Actually, I am thinking sedan. Is there a decent 4wd hybrid?

no 4/awd hybrid sedan exists that I know of

The only Hybrid Sedans with AWD are the Lexus 600h at over $100,000 or the Infiniti Q50 which is coming as a 2014 for about $50,000.

So far awd hybrids are rare because hybrid buyers want maximum mpg and awd is hard on efficiency. The few luxury cars that offer the feature have complicated systems with multiple electric motors. So you have to decide which feature matters more to you. The Legacy is a nice car, if not super fancy.

The new outback is bigger than the previous version but it is close in size to the Legacy sedan only raised up to feel more like an SUV. If you prefer a sedan than buy the Legacy. You can buy AWD Sedans from Ford going up into the Audi/BMW/Mercedes end of things but the hybrids are mostly 2WD at this point.