I'm always a sucker for fast outfielders so Luis Matos, Jeffrey Hammonds and David Newhan have to be at the top of my list: None of them were actually good but Newhan did provide us one of the best highlights in sports history with the Manny cut-off. Hammonds was probably the best of the 3 but I remember jumping on the bandwagon early after receiving a Home Team Sports sponsored photo giveaway at Camden.
I also have plenty of least favorite unheralded Orioles but probably too many to name. A select few include David Segui, Larry Bigbie and Jay Gibbons (notice a theme). Alan Mills also yelled at me from the bullpen when I was a kid one time so never been a fan of his either.