What are some good wads with custom weapons/monsters besides KDIZD and UTNT? 

http://doom4ever.free.fr/ 

I don't know many. Satanic is a great TC, but no new levels
http://www.doomworld.com/idgames/index.php?id=15618

The older Osiris has nice sound, enemies and weapons, but level design is bland http://www.doomworld.com/idgames/index.php?id=6711 

Marble Blood ... Pretty good. 

I have stumbled into this:
Doom Postmortem by Tom Hall and John Romero - GDC 2011 

Eye of the Storm. 

haha, I posted about that ages ago! I actually did find it, and the map is much worse than I remember it. :P 

http://www.realm667.com/index.php?option=com_content&view=article&id=1460:the-refinery&catid=34:projects

More KDIZD-like stuff. A large, visually-impressing remake of E2M3 with typical excessively hard and unfair gameplay. For GZDoom 1.6.0 or higher. 

Those screenshots are way too dark. 

hmm yeah mostly hitscan enemies, bugger all health, uninspiring placement of monsters/fight design and confusing layout.

Pretty though. 

knows how to make a pretty map. 

By the way, the Community Chest 4 megawas was released a couple of days ago as well. 

Looks great - interesting enemies, but not promising when you're massacred by a mob of teleporting ghouls in your first encounter. 

I was talking 'bout Tormentors map.

Up to map 7 - Hoedown - on CChest4 and it's starting to heat up. Nice stuff :) 

Keep at it. As usual it's quite a mixed bag. Some very average maps, but also some very nice ones. My favorites so far are 08, 10, 14, 18, 20. 

Yeah, 20 is a bit of a bizarre sci-fi themed epic. But they backed it up with similar in 21, which just doesnt work.

Loved map 24. Solid gameplay and detailed base level. 

I played the beta a while ago. It's great stuiff.
http://www.realm667.com/index.php/community-news/1626-zdcmp2-v10-released 

Got back into Doom wads recently after finishing Doom1 and Final Doom. Going Down is the first wad I tried in I don't know how many years.

Link: http://www.doomworld.com/vb/wads-mods/65955-going-down-final-episode-updated-sep27/

tl;dr: Going Down is a fuckton of fun with some really inspiring level design.

Going Down is a 30-ish level .wad for Doom2 by mouldy/cyriak. Yes, that cyriak. The Welcome to Cat City cyriak. I don't know if mouldy is cyriak or if he just did the custom music for the wad or what, but the levels certainly have that schizophrenic quality you see in his videos.

Anyhoo the idea around this map pack is that you go to the top of this building, then descend, floor by floor, to the bottom. So the maps are pretty small but full of bad guys to mow through. I don't want to spoil it for you, but the level design is pretty innovative (I guess, I haven't played a lot of Doom maps to compare) and the maps don't become stale at all.

Combat mostly sticks to horde-style. Like, sometimes 500-800 kinds of numbers in a couple of them. But mouldy changes the pace in several maps with smaller numbers but more interesting game play elements. Again, I don't want to spoil it, but the levels get pretty mind fucky. I actually thought I dropped acid during one level. Not for real, but like, it certainly felt like a Doom version of dropping acid.

The only thing I kind of got tired of was the music. Cyriak is great and everything, but basically it's listenting to 3-4 hours of Cyriak while killing hordes of demons and stuff. I just found his style tiring after a while. The music isn't bad or anything, just a bit repetitive for my tastes.

You could totally play it in an afternoon or break it up into smaller chunks over a couple of days, like i did, but I don't think you'll get bored of it. It's a solid map pack and plenty of fun. 

Since Zwiffle is recommending wads, http://doomworld.com/idgames/?file=levels/doom/Ports/d-f/draftex.zip

I'm on the final level of this now, haven't had the time to sit down and really address it. Draft Excluder is for me, tough. Not beat my head against the desk tough, but rather "Wow, I didn't realize I could do that..." tough. The maps are pretty linear, but they have enough going on with fun combat that this isn't a serious negative. Impressively, while being restricted to the Doom bestiary, the combat doesn't get old. Secrets are plentiful, adequately hinted at, but not always obvious. I consistently felt an accomplishment from finding them, and I didn't find every single one.

I'm on the last map now, and... it looks a tad crazy. I shall see how I handle it. I played for 20 seconds and encountered four Cyberdemons, a couple of different hordes, and heard a Spider Mastermind... Don't let that scare you from the WAD, the final level is obviously a tonal shift from the rest.

This made it into the 2014 Cacowards Top 10, and I see why. 

Just because you mentioned them.

http://www.doomworld.com/cacowards/

I like them because it's a pretty good filter to find the best Doom Wads out there without a lot of hunting around plus they link to the wads themselves so no need to go looking for them. 

going down is in my opinion a must play. But I think the latter levels gameplay isn't as good as the rest. Still liked some of the ideas for the settings in the final levels, especially the dark corridors turning to hell and the hellish city 

I really didn't enjoy Going Down. I think the skill level of Doom players has passed me by, I found the lack of ammo and health makes it far too difficult for me. 

Other than a couple of levels (Indigestion, mainly) that GD had an overabundance of ammo and health. But I didn't play on hard mode or anything. 

I always play through on Ultra-Violence.

For me Doom has never been about showing restraint or conserving ammo, it's been about dealing with a fuck-ton of enemies and surviving against ridiculous odds. But somewhere along the line this got lost in some wads and now ammo needs to be conserved a crazy amount. 

Skill levels exist for a reason.