Best duo?

[Stonal]

by far IB/WP

[JediRift]

by far IB/WP

This one is really good also. Though I prefer the IB/RP combo. I like the RP healing toolkit a bit better, but again, that is personal preference. IB/WP is just as unstoppable.

[lilsabin]

ironbreaker+inronbreaker , loooool

[Euan]

DoK/Chosen is the best. You say Destro is overpopulated but there's actually more order.

[Luth]

Spoiler:

[Joan]

Cory has already mentioned it, but
Blorc + Choppa is a really solid choice.
The Black Orc can protect and help the Savaj Boy very well. Armor debuffs + KDs are the bane of the backliners.
How does this duo fight? (Da Bestest Plan!) The Blorc points at an enemy (Oi, hit 'im) then both Orcs rush towards said stunty (Hit 'im again!) and they smash it. Rinse and repeat.
Its the magic of the WAAAAGH!

[gotharg]

IB + dps WP

[Sulorie]

No idea what I shall say to people, who suggest duos without a healing capable class. Oo
Do those setups work in puglandia?

Who says anything else than SW/dps AM on order side should feel ashamed, when talking about the best duos. Followed by dot BW/RP(better cc that WP).
Ranged duos > melee duos, because it is easier to manage larger enemy groups with kiting.
That said, other setups can make fun.

[Noiree]

SW + dps AM or SH + dps sham

[noisestorm]

Pretty much what Sulo said. SW+AM and RP+BW are pretty solid. I myself had a huge amount of fun duoing with my friend's BW as AM in t3 though. BW later on also gets his CC, huge damage and also a weak healdebuff.
BW compared to SW for you, in a few words: SW has overall more sustained (but lower) damage while moving (high burst while standing with m2 and scout spec though). BW has a lets say delayed burst that can pretty much oneshot people if they dont get cleansed soon enough.
Another good thing: AM and BW both have the same type (Hex) which protects the BW dots better than SW stuff