If you need more Medieval - BKB's and XL are the mod for you. MedMod is very good too, but somehow smaller than both before (only 2 campaigns).

The rest are total conversion mods - changing tha timeperiod and often many, many other things.

Samurai mod - basically STW on MTW engine with many new additions you can't find in STW.
Its main advantage is the timeframe and the place you are fighting - Japan during the civil wars.
Major flaw (to me)- small number of units, though well balanced and difficult.

Napoleonic TW - v7 allows for more than earlier editions. Over 180 new units with excellent new animations, new techtrees, over 30 historical heroes and interesting features such as historical battles, new battle maps and movable artillery and rockets.
Flaw - unhistorical starting positions, the fact that the AI poorly uses missile infantry with good melee and old MTW provinces with only campaigns different by set up rather than anything else.

Hellenic TW - Completely new campaign map, large number of units with new animations ( chariots, elephants, ram and other) of superb quality, excellent battle maps, interesting historical battles and numerous factions to choose with different fighting styles. It is also pretty difficult.
Flaw - CTDs in some cases.

Fall of Rome - simplier conversion which has smaller number of new animations ( Legions, new steeds etc), but its difficult compensates for that somehow. Some interesting ideas (new use of crusades) and interesting campaigns are also the good points of this mod.
Flaw - less advanced than the rest, but good to try.

Middle Earth TW - simply amazing battle maps ( MORIA !) and brilliant animations ( Trolls, dwarfs, elves etc).
Flaw - no campaign, smaller number of factions, some units are missing ( Ents...)

Pike and Musket TW - placed in the period between 1480 and 1700.
Huge number of new units ( over 700), factions (about 55), historical heroes ( over 200) and unit animations. Some unique ideas ( warwagons, ski troops, field fortifications, new 'dismounting' system, entirely new ideas for buildings), very historically accurate and difficult with some factions. Some new historical battles and more or less evident advantages.

Flaws - some old animations, map from MTW XL so not so realistic as should be, old battlemaps and very low, but still existing propability of a CTD - the price for the size of the mod.


If I forgot something I beg to apologise...

That should be quite insightful and reliable review.

Regards Cegorach