Most irritating enemy faction?

[Zharakov]

In my game as Sythia - The Germans who held me in Russia for 80 years

As Julii - Britions just because they never let me land on Brittion, I only wanted to talk...

As Carthage - Numidia just because of how fricking huge Numidia is

As Armenians - Selucids and Egyptions tie because they allied against me after THEY attacked one of my fleets

[Uesugi Kenshin]

No matter what my most irritating faction is the romans, I always end up fighting at least two of them at once. Currently I am waging a two front war against the Scipii (North Africa) and Brutii (Greece, Italia), it takes me hours to capture a settlement in each area. Hint for those annoyed by the Seluecids, if you start on their border blitz them. The Seluecids start the game off weak, they have alkmost no way to counter archers or cavalry. So if oyu are Egypt what you should do is have light infantry hit the front of their phalanxes and then charge the rear with cavalry or just use archers to kill them from range. As the Britons the Julii have kept me from making significant gains in Italia because the Britons do not have heavy enough troops. If you are on the border of a faction that can become extremely strong mid to late game the best strategy is to force a decisive winner takes all showdown. Do not have a cautious game plan throw all of your troops into the grinder, make risky decisions on the battlefield, bottom line don't bleed the tough factions slowly decapitate them and burn their corpse. Beat them until there is nothing left to beat. Never allow your economy or population to come in the way of your military's need for a quick and brutal conclusion to a conflict. If you find yourself thinking, "But if I lose I might not recover..." you probably have the right idea!

[Paul Peru]

I think it depends a lot on who you play. As Armenia, Seleucids and Egypt are very annoying. They just won't take my peace offers. Parthians demanded 3 cities, but then settled for trade, map and 1000D. Pontus won't hear of peace either, but I've got them walled in. Eggies and SE are swarming me with chariots and pharaos elephant desert whatsits. I'll wote for Egypt, since I actually attacked SE first. GC are annoying too, with their bribing habit. I've never been annoyed by Scythians or Thracians.
(The list seems to be missing American Bushii)

[Rosacrux redux]

Egypt is annoying and irritating anyway, just because of their pharaonic buildup and their stupendous unit lineup (even though by playing the Total Realism Mod I don't have to live with the stupid names anymore - I do have to live with the ridiculisly overpowered "native" units though) they are way too overpowered in vanilla RTW, their levy units are better than most factions top notch units, they attack the Seleucids out of the blue, even if they were allied for only a couple of turns (you can tell I've played a couple of Seleucid campaigns, can't you?) they bring in army after army after army... did I mention I hate the "pharaonic colour" of this faction?

Also, when playing as the Greek Cities, I find the Brutii (allthough rather weak) extremely irritating. They will land a smallish army in Athens every other turn, besiege, get trashed, repeat the next turn and over and over again... I really hate this.

[Paul Peru]

In my game as Sythia - The Germans who held me in Russia for 80 years

Don't you like it there?

[Somebody Else]

Egypt, as they seem to be able to reach 15 provinces fairly quickly - and defeat the Seleucids. A problem if I've got a slow starting faction and I want to play a short game.

[Heinrich VI]

egypt - hands down! they are always annoying to fight and their citys are prone to revolt all the time.

[The_Emperor]

Egypt...

They are able to spam armies and have money to burn. Plus those Desert Axement with their "Armoured Skirts!" really annoy me.

The next most irritating faction would have to be anything Roman!!

[Basileus]

Gauls annoy me, they breed like rabbits and will never stop sending huge stacks of inf armies at you heh

[Khuyildar]

Germans. They have too good units, which, unfortunately for them, causes me to take pre-emptive action against them early on. They would surely attack me anyway.

As a disgusting off-topic, I love the Gauls. They keep sending huge stacks of useless infantry, like warbands. chop chop

[Parmenio]

Egypt - just because they're so historically wrong.