Agree on the Dobsonian on being a great entry level option unless you need to be mobile. You can still be mobile with a smaller dobsonian, but the bigger you get, the harder mobility becomes.
I think 6" is still pretty manageable for most people--you can probably fit it in the trunk of a sporty two-seater car. It's really only when you get to 10" and beyond--telescopes that are probably not a good "first scope" purchase for a variety of reasons--that the Dobsonian becomes a beast.