The games you speak of were designed to be perfectly playable on keyboard only, so just about any gamepad should work well, really. Personally I'm using Xbox 360 pad for them, but Steam controller is supposed to work damn well too (altho I'm pretty sure it doesn't work outside of Steam, does it?)

It's not just up-down, Doom also contains horizontal auto-aim

Of course. It can be disabled via cheats IIRC.

I would also like to recommend the Steam controller, the reason is that you can customize it to whatever you want, and if you don't want to deal with the customization part, then look for a template form the community.
Other than that, I got it for the Linux support, and my XInput controller broke.

Sorry, I am not following this either. Played FPS for decades now, and don't remember any autoaim until recently. Me personally I can't stand autoaim, had it recently in a game, and the bastard thing kept aiming at the wrong target. M+K is the only way to play these, and yes have tried twiddle sticks on many consoles, they just don't work as well - although 3rd person such as RE4 was ok.
As for Steam controller, isn't that PRM (Physical Right Managment) linked to Steam client?

I'm all for controllers but classic FPS and controllers don't belong in one sentence /thread

Your memory is just colored then, auto-aim has been a fairly standard feature at the very least up to the original Half-Life. Doom had both horizontal and vertical auto-aim, just about all build engine games did as well. Generally speaking, whenever a game defaulted to keyboard-focused controls with no crosshair like majority of early FPS games did, it had auto-aim. After Quake exploded, most fully 3D FPS games still had auto-aim implemented, like Unreal or Half-Life, it was just disabled by default. Since FPS games made a transition to consoles in Xbox and PS2 era, you could say auto-aim never really went away.
Just a quick search:
Doom
Blood
Quake
Unreal
Half-Life
Yeah, most of it are not actually good sources, just a confirmation that memory is not fooling ME.

That just means you suck with it :-P

Consider using any controller you find ergonomic and just use a good quality keymapper to setup what you want. For example, Pinnacle Game Profiler is great. Though I don't play fps games, so can't speak to that. There is another newer keymapper like Pinnacle as well. I think at least Pinnacle also supports joystick and other stuff but I haven't used games needing those. Anyway lookup keymappers for your needs.

Basically if it had keyboard only controls, it featured auto aim. So you're looking at the sprite shooters. I think most of them have the option to turn it off though.

Ok, I must have turned it off for them then. Strange, as played blood recently and don't remember it. Oh well, if in doubt turn it off :o)

It definitely features in blood. Especially if you use to flare gun.

It's really easy to miss in Build engine games and Doom tho. There's no visual indication of auto aim and it doesn't move your crosshair in any way - you just shoot and feel like badass for hitting so well, which I imagine was the original intent

It is very effective that is for sure. Especially if people haven't noticed to this day.

Yep, but then you get old and realise your just a portable sack of poo with an ambition to be an expensive funeral
[/happy though for the day]

Thanks for the responses, everyone!

I'm looking forward to getting back to Red Light District, et al.