A lot depends on the type of work you do, but I have really taken to like gas shielded flux core, AKA "dual shield".
It can be hard to find in smaller wire sizes and smaller roll sizes. Realistically it may not be an option unless you have a 250 or larger floor model MIG welder. But once you try it there is no going back.
It's very fast, faster than regular mig or flux core. It penetrates like stick welding, and it makes beautiful welds with the ease of using a caulking gun or hot glue gun. Welding vertical and overhead and bridging big gaps is a joy to do.
But then again when reading anything I suggest keep in mind I'm someone who works on rock crushers....
