payn
I don't believe in the no-win scenario
Many of the Paizo adventure path modules can be stripped out and run as stand alone adventures. Serpent Skull, for example is a path I wouldnt recommend due to it having many problems down the road. (There are some real world behind the scenes issues at Paizo that can account for why this happened). However, the first adventure (Souls for Smugglers Shiv) by one of the best in the biz James Jacobs is a great starter adventure sandbox that could be converted easily to other editions since early levels are the least work.I miss the 32-64 page modules of the olden days. The campaign adventures (and adventure paths) get too convoluted for my tastes, and I lose interest.
Im not sure if the WotC published adventures are as modular.