Montezuma 6. It returns to a previous map. Plus it would be an epic online map.

Plus Attila Siege of Constantinople another epic map for online.

Saladin definitely has some of the best, 6 is indeed absolutely epic, and Horns of Hattin is one of the most unique and memorable missions which somehow manages to be both chaotic and still strategic at the same time.

I don't think I could pick one favourite, but a few others coming to my mind (and yes I like the previous DLCs a lot):
- Hautevilles 4 (Bohemond in the East) - the best defensive mission in the entire game. It's truly massive, glorious and it requires you to control A LOT while still being a real defensive mission. I had a stupid grin while sweating a little the entire time.
- Jadwiga 5 (Vytautas' Crusade) - I could probably just list the whole Jadwiga campaign here, but this mission is the best of the best. It's as intense and balanced as the whole campaign, but the twists here are AMAZING. Sudden twists are often either not that hard to overcome or annoying, in this mission it was absolute OMFG HOLY SH!T in a way that was both fun and actually required adapting quickly.
- Jan Zizka 4 (The Golden City) - this was brutal in the best way possible. Probably the only mission where I still had a lot of fun while there were Teutonic Knights breaching my walls and I had to manage three fronts at once. This campaign is just a textbook of how to make a difficult campaign which is fun first and foremost, and this mission is the best example.

Crucible.

York. The map is HUGE. And you can choose different starting locations for your initial base, and each location is basically a different difficulty setting within your chosen difficulty setting. Try starting a base in southern ireland, for example, instead of easy noob mode that is landing somewhere in scotland or northumbria. The only thing that usually makes you win after a certain amount of playtime is having accumulated 50k gold. If you keep selling your gold (or ungarrison your relics), you can take your sweet time and raid all the major cities in England AND ireland with all their impressive cathedrals and cliffside castles to your heart's content using a roaming band of health regenerating elite berserkers.

Personally, I love "Brother against Brother" from "El Cid". I just remember it for the intro tournament and how easy it is. (Perfectly KISS. Keep It Simple Stupid. A very Noob friendly campaign.)

Attila 1 for an Ally that works

Hastings bc I love the history behind it. Bonus points that it also 'includes' the Battle at Stamford Bridge

My favorite so far has been Rajendra Mission 3. I played it on moderate (as I do all my campaigns) and I never had so much fun in a single other scenario, ever, because I got almost wiped out but clawed myself back step by step to eventually dominate both land and sea (and also because Dravidians arent a civ where you just spam paladins or load up unique units in rams if they are infantry, for the win like with many other civs):

With Aoe 2 scenarios you either struggle all game until the lategame push and dont want to repeat that scenario ever again, or you are on easy mode the whole time, or you find yourself bossed around by the objectives one by one as they appear, not knowing what comes next.

But in this mission, which felt like a mini-campaign, you are given free reign to play as you wish over a map of entire south india that includes sri lanka and the burmese and malay coasts as well.

At the very beginning you have the choice of either making a beeline across the Bay of Bengal for Tanjavur taking high seas attrition, or sail along the shallow coast and fight bengali pirates.

Once in Tanjore, you have two town centers, one above and one below Rajendra's palace and both are quite exposed to not just bengali raids from the coast, but Madurai's ships as well that round the southern tip of India and sail up from the south to harass your east coast, while their crossbowmen and elephant archers harry your villagers trying to chop wood nearby.

Madurai itself is a walled city sitting uncomfortable close to your bases, but your attention is also distracted by your northern Vengi ally attacked by Chalukkya forces coming from the north.

Then you are told to build a castle near the Tungabhadra river to keep Chalukkyas from pouring down from the northwest, while both Sri Lanka and Vengi eventually turn on you. Beset by foes on all sides and your gold and stone dwindling, you have to earn back Prestige Points by earning back their fealty, which usually involves damaging their castle. Trading with Sri Vijaya by 1) number of trage cogs, 2) number of trips made, and 3) amount of trade gold earned is also counted towards prestige, just like rooting out the bengali pirates from their base in the Andaman islands and having a standing armada numbering 40 warships.

It was a challenge that lasted for several hours, but only because I refused to boom and am not a great naval player compared to land and relied on towers full of heated shot archers taking out enemy ships than doing so with a fleet.