Best mod/overhaul for balanced, difficult play through?

What the title says. There’s so many cool looking mods and gameplay overhauls. I’m curious to get an opinion from people that have tried some. Which mod/overhaul do you think is the most balanced and difficult? Preferably one that adds new classes. Thanks.

Grimarillion mod comp.

It offers:

Cornucopia - Game balance changes to items, devotions, and the base 6 masteries.

Grimmest - Increased mob density

Grim Quest - Additional masteries, artifacts (relics), spear and staff weapon types.

Zenith - Additional masteries

D3 - Additional masteries

Another vote for Grimarillion.

As if I needed another reason to completely neglect all of my other games, as vanilla GD was doing that enough. But, here we are. Yeah, it’s pretty damned awesome.

I also second this. Variety explosion! Also Grimmest looks like it will make co-op really fun so I’ll be trying that once I convince a silly friend to stop playing D3…

I was going to try DAIL but Mega link was broken. Will try again soon.