Well, I remember the palace entrance. It's the first thing that pops into my mind whenever I see discussions like this one.

Typically, it's also the last. :) 

The Palace entrance is the obvious one.

The power plant with the explosions going off above the two huge chimneys.

The hangar map with the huge shaft, the Hornet boss in it, the lights going up the shaft, the top doors that close, then out to the Black Hole Generator in the next map.

The train in the Lost Station (it doesn't always have to be outdoors, you see).

All the places with towering architecture and fascist banners. Faces and crossed fists. Opulent carpeting. Brickwork. I could literally go through every map and pull out other examples that are being ignored, but maybe it would be "just typical mh contrarian trolling", eh? 

This is the thing though, and yes you can step through Doom 3 in the same way, and say things like "but Delta Labs is totally different to Recycling" etc, and be correct to a certain extent, but.... the overall impression of the game, the impression that most people come away with, and how they think of the game when they look back on it, is one of overall homogeneity. 

Doom 3 has a similar problem: technically, the themes are different, but the levels are constructed in such a way that it all feels about the same.

There are tons of architectural motifs that are repeated ad nauseum throughout all the maps, which contributes to the sense of everything all blurring together. I swear 90% of the brushes in Doom 3 are pipes, railings, and slatted steps. 

My memories from playing the game in 1997-1998 era:

The cooling facility (and the other waste processing levels) impressed me the most. Probably because it's the stroggified expansion of the wind tunnels theme from quake 1.

The jail level was cool, though it lacked variety. But it did have big heavy stone shapes and oppressive angles that I liked.

The big shaft with the hornet boss was cool/memorable as mentioned above.

The low gravity space level was a cool moment even though I think it was pretty basic architecturally.

And the very first level of the game is pretty memorable since it was the demo and established the iconic quake 2 base theme. 

Have a sense of place that is fairly immersive and makes progression pretty fun imo. Quake lacks this somewhat. 

Quake has less of a sense of "journey" because the levels are more self-contained. I'd never consider quake less immersive than Q2 / D3 tho. 

Feels very "padded" to me, with particular emphasis on the stretch from the Intro map through to Delta 4. After that it does tighten up a lot and we get good variety (but not enough of it) with the excavation site, the caverns, the ancient ruins.

But it could have done without at least 2 maps in each of Alpha and Delta labs, and some of the other areas that are two maps (Communications, Recycling) would have been better as a single map with the fat trimmed.

A bit more outdoors, a bit more Hell, a bit more ancient ruins to expand things out again and IMO it would have been a much more enjoyable experience. 

The first Quake displays the same sympthoms, TBH. It even has the reputation of a game that's entirely brown (although ironically it doesn't have a lot of actual brown). 

If you were to compare Doom 3 to one of it's contemporaries, Half Life 2, I think there's an interesting contrast. The change in environment in HL2 goes hand-in-hand with change in combat. In order the main combat sections went:

Canals in urban area (on foot, low powered weapons vs combine)
Canals in outlying area (in boat, long helicopter chase)
Creepy abandoned town (zombies vs gravity gun and traps)
Coast road (in a buggy vs combine and antlions)
Prison (on foot with antlion allies or Alex)
City 17 (leading squads vs combine with Striders)
The Citadel (super gravity-gun)

It wasn't just the environment which was fresh, it was the gameplay too, and the interaction between place and gameplay reinforces that. I'll admit I haven't played Doom 3 as much as Half Life 2, but the combat all blurred together like the environments, the only parts that I remember feeling different were the bits where you were outside with limited oxygen. 

I think anytime you recall levels or missions from a single game there's a tendency to want to believe they all looked the same, because in a way they do.

Most games are made with a specific overall "style" from the beginning. I think this is called "art direction".

But if you actually go back and replay those games you see that they were in fact made up of many unique and interestiong locations. 

When you can only see it on your second/third/tenth playthrough, well, I don't think it's merely art direction. 

Most games are made with a specific overall "style" from the beginning. I think this is called "art direction".

I tend to be more interested in the artist that paints a variety of landscapes equally well, rather than that guy that only ever paints oak trees with a horse standing underneath. 

personally, I just can't get enough of horses under oak trees :D 

I tend to be more interested in the artist that paints a variety of landscapes equally well, rather than that guy that only ever paints oak trees with a horse standing underneath.

But what if there was also a lion and some cows too? 

roger dean still waits for my U1maps thanks to the broken editor. 

Goddamn, I love all that 70s style of fantasy art by people like Roger Dean and Rodney Matthews.

A colourful, modern take on Unreal 1 that looked like that, would be better than all those desaturated grey/brown greeble games that the Unreal engine just turned into a factory for. 

But... 

Yeah for some reason during the unreal engine 3 cycle, every game had a complete hard-on for sticking a post-process filter on that sucked the colour out of everything in the scene and made the whole screen the same hue. It made Quake look positively colourful. 

Honestly, the Quake games were a lot more colourful in comparison to the GoW games and UT3 etc...

http://i.imgur.com/y5464dA.jpg
http://i.imgur.com/VhFJVNh.jpg
http://i.imgur.com/U5DjHke.jpg 

quake's colors are fairly saturated. They're certainly not garish or even vibrant, but they're not as dull as some make them out to be either. 

I like the Quake palette. Although some of the more vibrant colors weren't used all that much. 

Dunno, I think the Quake palette is one of the worst designed palettes I've ever seen in a game.

The pink/purple stuff was a massive waste of time, as was the cyan, yellow and bright blue lines.

And of the colours they actually use in the game, there's a ton of redundancy across the similar brown/green shades.

Ugh, such wasted potential. 

...the more monochromatic textures anyway.

Then there's the brown that is comprised of green and purple... that's fine from a distance, but at close range there's no way you're gonna make that look good. 

I've heard people saying that Quake 2 palette is better. I dunno. Maybe for amateur player skins or something.

In any case, there are uglier palettes than in Quake.