Well Feyenoord is the obvious one. I also like some of the other Dutch teams like Heerenveen (who's got a great attacking style). Some teams that earn my respect because of their fan attitude are Twente, Heracles Almelo, Groningen and Utrecht. Besides that I'd like to see all 3 Rotterdam teams doing well, so I side support Sparta Rotterdam and Excelsior as well, however I don't feel any pain in case they lose.
Outside of the Netherlands I do have my favourite teams, but the same counts for those teams. I don't feel any pain whenever they lose, but whenever they win you would be able to see a smile on my face from time to time. I have one of those teams in pretty much every league. Some leagues have more, others have none
Some of these teams include teams like, Yeovil, Rotherham (because it's almost Rotterdam), Wycombe and Inverness Caledonian Thistle. As for the bigger leagues I go with teams like Liverpool, Toulouse, Lecce, Boavista (no longer in the highest league though), Celtic and Barcelona.