A combination...

I need two classes that work well together, are fun, and can be used for farming when necessary. I'm using NF, any suggestions?

Depends on what you want to farm. Monk and Assassin are the 2 classes with the most farming options, but Elementalist and Necro have quite a few, as does Dervish and Warrior. Seciondary varies a lot, but Monk secondary is used for 55/600 builds and Ritualist is used for a few as well. This isn't really a question that can be answered easily. I'd say Monk would be the most obvious, but secondary would vary on what you were going to farm with it.

You only have nf? I would say you are very limited then and would probably suggest derv.

No, I have all 3 campaigns.

I would suggest Ritualist. You have the Spirit Spamming farming, which can farm nearly anything, as well as the 330Rt, which has a lot of options, as well. And, you can 600/smite as a Rit using VWK faster than you can as a monk. My Rit is my main farming character, and I love it over any other.

I did say I am on Nf.

Yeah, but you also said you have all three Campaigns. So which is the case?

Dude you said you have all three campaigns...make a rit or assassin and start in factions, and later you can transfer over to nightfall

I said I was startingg in Nightfall, and I have all three factions. It's extremely simple.

Go make a Mesmer it's just so much fun when you watch someone's build come crashing down causing them to kill themselves or you can go secondary monk and spam healing skills tobe everyones favorite

Necromancers can be used for almost every caster build.

Try casting spell breaker for the dungeons that are worth running on 0 divine favour and it wont work.
Hence monk primary benig better overall as they can use a decently timed Spellbreaker, and you dont lose another party slot for a seperate Spellbreaker-er.

OT: There is fissure of woe solo paratrooper if you make a paragon, not sure on dervish but you are quite limitted as most of its underworlds builds have been made MUCH harder due to the arrival of the skeletons of dhuum.