Pre-Reforms: archers, velites, and Merc Phalanx
Post-Reforms: the same (except velites are called something auxilia) plus cavalry auxilia.

I just use my superior economy to wear them down.

Well, after the reforms, legions in Testudo along with skirmishers to protect them from charges probably work the best for me. A few Archer Auxillia are helpful, but they will suffer heavy casualties along with the skirmishers, so it is a judgment call.

Pre reforms, you are best off avoiding them wherever possible. Mercenary phalanxes are good, but try to avoid Egypt, especially in the open field. You could probably beat them in the cities, but they are pretty overpowering, so I typically just wait.

Good luck.

Well balanced large Egyptian armies offer the hardest AI challenge in RTW.

I use forts and cities a lot when advancing against heavy concentrations of enemy. Egpyt is no exception. Wall towers of fort/cities will obligingly deal with many of those Egyptians.

If I have to fight them fair then luring the heavy chariots onto phalanx formations is the way to go. Enemy chariot archers are more skitish. I have to let many of them get away. Sometimes they will chase light cavalry...lure into wall tower range or phalanx.

Good luck

A nice trick to let chariots run into your phalanx is to attack them with wardgos, then when the dogs are released, place the handlers behind the phalanx. When the chariots have killed the dogs (don't worry, they will get healed after the battle), they will go for the handlers... And thereby crash into the front of the phalanx.

Mercenry Hoplites are what you need - Velite gladiators are handy too, as are Triarii, while Velites and archers will inflict damage from a distance. Because of their range, Cretan archers are particularly good.

To be honest though heavy infantry on masse is the best way to kill charoits - if you can stop a chariot, it's as good as dead. Load of infantry will stop a chariot, and kills it before you take many losses.

Three ways that have helped me.

1. Lots of archers or good archers. A few javelins wont hurt either.

2. Mass Cavalry on charge. Chariots die really easy in a melee. When I fought the Egyptians on my Julii campaign, I used 2-3 (at the least) cavalry auxillia, roman cavalry, or equites to go and charge the chariots. Dont let them charge if you can help it. This is how they massacre units.

3. Most effective way is phalanxes. The Greeks against chariots are amazing. In my Greek campaign, I fought Pontic chariots with pikes, and my pikes chewed through them very fast.

Gladiators and Arcani work best for me.

Missile troops and javelin cavalry are also useful for this. If going the merc route I hire some horse archers in scythia and send em to egypt.

I've always found testudos and cavalry auxilia to do the trick.

Edit:
Had to dust this off!
http://rtw.heavengames.com/cgi-bin/forums/display.cgi?action=ct&f=2,2177,,all

[This message has been edited by Santos I (edited 10-02-2007 @ 05:34 AM).]

Mob them. Stopped chariots are dead chariots.

Not much experience with Romans, although I did play a Scipii short campaign wherein I destroyed Egypt. I usually got them in the cities and picked them off with archers while triarii kept them at bay.

In a Parthian game I've been playing, Persian Cavalry are my resource for just about everything. In open desert, I will hit them with tons of archery before charging them with cataphracts.

I ran into a situation this morning where an Egyptian full stack caught me off guard near Thapsus. They came while I was trying to change my pre-Marian army to the post-Marian. I had just disbanded several units in Thapsus to make room for new unit costs and the Egyptian diplomat must have seen this because after I hit end turn there was Egypt's army. Surprise! What the diplomat didn't see was the 8 units of legionary cohort trained in Carthage with a pantheon to Mars that replaced them next turn. Ouch time for Egypt. Anyway, in their stack were 5 units of chariot archers and I hadn't trained my new archers yet. I had a few banged up units of roman archers in Thapsus, but they were only enough to account for the three units of bowmen in the Egyptian stack. I had no skirmishers in the area either, just heavy infantry and a few units of legionary cavalry. So I checked the available mercs before putting together an army to go save Thapsus from imminent attack. I got lucky, mercenary war elephants were available. I hired them, and to my surprise they were the most effective thing I've ever seen against the chariot archer. The elephants and heavy cavalry kept the chariots away from my legionaires while they did what they do best. Once the main body of their army was dead it was a simple matter to herd the chariots to places where they'd be killed quickly. When more merc elephants show up I'll hire them and send them to my front with the Britons, they should be able to rack up massive amounts of kills there.

Just another suggestion, if your economy can afford it.