The Tavern

victory dancing
item damage and destruction
nausea
five different kinds of chunks and dozens of kinds of food, none of which stack together in inventory
missile enchantments and brands eating up all your inventory space if you're going ranged
inventory filling up with 20 different kinds of wands that don't even stack same types together
Traps and secret doors skill.
weight/encumbrance

And who can forget these classics too?

* Ring of "I"m less hungry than I COULD be." (Sustenance?)
* Ring of "I'm a temporary Formicid." (Stasis)
* Amulet of "Middle Finger @ Orbs of Fire" (Resist Mutation)

Also didn't regeneration used to be a ring ego instead of an amulet? Or I may be mixing that up with something else.

controlled teleport to the Orb on Zot:5
only one rune requirement

Trudging backwards and forwards in the snow each day, and both sides uphill.

eino sending you a message every time you fight terpsichore

Stasis was an amulet, regen was a ring which was converted to amulet after amulets' reworkal and also in order to discourage its swapping - before the current mechanism of regen only after being at full health was introduced.

Tedium of sacrificing corpses to a god.

(P)ray

(P)raying before every single kill so that it would give you piety

Rods

I didn't even notice but what the hell, rods were great. They were like the only evokables that were fun to use.

Sublimation of Blood on corpse chunks.

Starving to death with a cursed Mace stuck in your hands.

I'm quite sure I still experience this, kids are stomach flu magnets

Getting horribly mutated on D:3 by Jessica with a wand of polymorph.

Praying to find a potion of cure mutation some day

1.) Killing monsters near some stairs.
2.) Carrying their corpses down to the floor below.
3.) Casting Twisted Resurrection on the corpses to make a bunch of little abominations merge together into a large abomination.

Oh! I almost forgot my favorite: playing mutation roulette with the potions you made as a Sludge Elf Transmuter. Remove Felid, bring back Sludge Elf!

You mean, before control-F let you automate trudging back to your stash?

Do people still make stashes? Is it still necessary?

Yeah, you need about 55-60 inventory slots for most characters.

But you don't need to make a stash any more, since Jellies don't spawn on cleared levels, you can leave things where they drop

It's not necessary, but I like to stash everything useful near each other so that I can Ctrl-G to my waypoint and be able to actually peruse what I've collected instead of making 267 Ctrl-F queries.

Apportating the Orb allllll the way to the closest stairs in Zot5.

You super do not need to stash in this game anymore.

The Hive!

I'm playing a Vehumet caster and I just remembered that you had to save the hive until you were ready to push into the last gifts because her/his piety decayed so rapidly.

Finding four silver runes in Vaults:5.

When was that? I know that in pre-DCSS Crawl there could be more than one slimy rune and several demonic runes.

The last level of the vaults had one silver rune in each of the four parts, this was a bug in a trunk version. I don't know the version number - I think it was two or three years ago.

Jesters,
Crusaders,
Several different types of Chaos knights,
Death knights,
Healers,
Stalkers (Along with fullsome distillation and evaporate)

Lava Orcs,
Djinn,
Hill Dwarves,
Mountain Dwarves,
Sludge Elves,
High Elves,
Grey Elves,
Ogre Magi,

Wielding decks to evoke them,
Decks of Wonder,
Decks of War,
Decks of Changes,

Enchanting a dragon hide to make it into a decent body armour

Darts

Ankus's (And starting with one as an ogre)

Evoking a Tome of Destruction

Hostile Ballistomycete colonies

Levitating (rather than flying) (Yay for flight, but you can't interact with items or go down staircases?)
Controlled Flight (Yay for the ability to turn levitation into flight?)

Being attacked by a mimic

The "Orc Slaying" brand

Elven/orcish armour

Portable altars, sacrificing selected items to Nemelex to get a certain deck, collecting all weapons to sacrifice to Ely, traveling and exploring only manually, searching for secret doors and traps, writing notes manually about where you leave different items (because there is no stack search function), getting killed by traps, starving to death because you teleported into an area in Orc with no stairs, getting killed by trying to passwall too thick a wall, zapping wands to identify them, divinations spell school, darts

no Noise bar!

Carrying books around for the sole purpose of burning them

watching someone lose all their TSO piety by hitting plants with a demon whip to find out its enchantment

Anti-training for opposite elemental schools.

Potion of beneficial mutation.
Cigotuvi's Fleshworks was the best portal in the game, also it was great feeling when you exited a zig with 10+ positive mutations.

Getting a knife just to be able to butcher corpses.

Someone mentioned sludge elves: I liked them too. I also liked killing balistomycetes.

Darts
scrolls of enchant weapon/armour could remove curses
weapons had separate enchantment for accuracy and damage
Items of Preservation
Boots of Jumping
Wands of Fireball - So everyone could start forest fires
Wand of disintegration - It could actually disintegration things
Wands of Haste, Heal Wounds

^ But some of those things were fun.

a spell failure rate of 29% being described as "Good"

I forget two things
Deeper branches
and
Vertical Orc Maze

Sharks that get all bloodlusty when they bite you!
Edit to add some stuff:
Having a secondary set of Armor to do Slime (corrosion was permanent)
Pakellas supercharge ability on melee weapons ...that was awesome!
Making a Jiyva-proofed stash on a permanent Tele trap with stasis.
Magic Mapping+Control Teleport making Extended sooooo much easier.

Mennas and other good uniques saluting you when you worshiped one of the good aligned gods.

Crazy Yiuf's hammers

Abandoning Kiku as a Mummy, but not before Twisted Resurrecting a bunch of corpse deliveries into bodyguards to wait out the wrath in Temple

New Crawl players will never get to experience...

... how easy it was in earlier versions to fight an illusion of my char, a clone woven by mara. The illusion clumsily hit me with a bread ration!

mara's summon illusion is still in the game and hasn't changed...

PleasingFungus fixing most bugs withing 24hrs!

Adding things to the game instead of removing things