Try Expanded Gameplay and The Eagle & The Radiant Cross.
Expanded Gameplay: very, very dangerous opponents. To give you a rough idea, there are troops running around with 200 str who mow down half a battalion before you can even react. To be fair, everything is scaled up - depending on your character configuration, you might have similar strength, etc. What this does is ramp up the difficulty of everything in the game, insofar that fighting a group of looters is dangerous - as one man taking on five should be, if you choose to engage them in hand-to-hand. Combat's basically a lot more realistic because of the ridiculous attributes of the troops - and therefore a lot more fun.
I like to play with manual mouse blocking, no horse, no shield, full damage, fast combat speed and battlesize 200 in first-person view. I'd never run into trouble with any mod until I stopped a party of LOOTERS in this mod who defeated me pretty much as soon as I reached them. It keeps you on your wits and is extremely visceral - I've added music from another mod (I believe Eagle or Lords and Realms, whichever had all the celtic Riverdance, Feet of Flames stuff) and More Metal, so it's all very energetic. This mod's 100% designed for those who like fast, frenetic combat though - there are many times you might get frustrated when you get cut down by the most unseemly of foes, but stick it out and you'll enjoy the rush more than any other mod. Seeing a block of Nords sticking together to ram into your scattered troops while unleashing battlecries to heal themselves is pretty damn enjoyanle.
Eagle: probably the most detailed troop design of all the major mods. There are very clearly defined factions and very well-thought out troops belonging to those factions, which leads to really good opportunities for strategy and tactics. For an idea of variety, you can have a line of pikeman standing in front of doppelsoldners, standing in front of archers standing in front of long-range gunmen flanked by cavalry. You could be standing nearby with your unique spear and a group of unique faction troops all clad in resplendent steel wielding broadswords. The combat in this mod is realistic and enjoyable because of the variety of ways everybody is able to kill you.
You're not going to get your ass handed to you in a one-on-one fight with any of the troops (unlike EG), but everybody's a lot tougher than your standard full-plate goon from any other mod. The brigade of the radiant cross are also pretty badass - riding in with/against them is something epic. I play this mod when I'm looking for more war-type fun - vanquishing the enemy in a big group with superior tactics or overwhelming power - as opposed to EG, where you do fight very large battles but are generally only focusing on your character's immediate zone and surviving.
tl;dr - Expanded Gameplay for brutal combat, Eagle & Radiant Cross for excellent large-scale 'war' flavour.
Don't listen to weak combatants who need to don full coat of plates atop a steel horse to brave a skirmish with river pirates.
