[LakeCleElum]

You want light weight, moderate power and low seat height to get started and be comfortable. The seat height thing rules out most modern endro/dual sport bikes.

You say "long-term", so assume you want to keep it a year or two before moving up? I'm not a fan of the "cruiser style" at all, but they do sit low. Any of the 4 Japanese companies make really reliable bikes. I'd say anything from a 400 to 650cc that you feel comfortable sitting on, making sure you can put both feet flat on the ground. G'luck...