I like to play these type of games using an XBox 360 gamepad on my PC. Is that supported in this version of the game?

Yes. You just have to choose it as a controller in the options and then you're good. With one noted exception, the controls are tied to the profile so until that has loaded you're on kb/mouse.

I'm using the wired controller and the triggers work fine without any remapping.

I haven't tried with the GOG release, only the Steam one. But while my gamepad mostly worked fine there, the triggers weren't supported; I had to map them to the bumpers instead (which are unused in AC1).

Supposedly this is only a problem with the wireless 360 controllers, and the wired ones work fine; but I only have wireless ones, alas. :)

I played with my F710 and it did have some errors, including triggers being unmappable and the defaults being way off. However, the files found here fix this problem.
More info on what they are and how they work can be found here

If this helps further questions, I played with a logitech dual action with zero problems. Yep, that old boy; I was under the impression the game actually used direct input instead of xinput. If anyone only has a xbox controller the fix above will help.

The game seems to work perfectly with Logitech F310 in DirectInput mode, without any fiddling. Even the action button color mappings in the game (green, blue, orange, red) map to the F310 color buttons perfectly then.

In F310's XInput mode (ie. the XBox360 gamepad mode), it is erratic (e.g. triggers used for moving camera sideways? Hardly.) and the button placements are way off, e.g. "button 7" which is used for high-profile actions is the Start button. In DirectInput mode it is the lower right shoulder button (trigger), which works much better when using together with action buttons. After all, I don't have two thumbs in my right hand. Also the colored action buttons are wrong in Xinput/XBox360 mode, like the green button which is supposed to be a sprint button, is an attack button, etc. In DirectInput mode, the buttons are in correct places.

It seems clear to me the PC version's gamepad support was designed specifically for PS2-type DirectInput gamepads, not XBox360 (XInput) gamepads. The fact that the game keeps referring to the buttons as numbers implies this as well (PC games designed with XBox360 gamepads in mind usually talk about color coded X Y A B buttons etc.).

I played it with the F710 in XInput mode and had the prompts being color coded, though I did run into the problem mentioned in post 4. It is possible that AC does support both DirectInput and XInput, which would make it (even more) lovely :)

Did you try to play it also in DirectInput mode? I don't know if 710 behaves differently from 310, but with my 310:

XInput mode => the controls are mostly way off, buttons in quite odd places etc. (and if I recall right, the triggers move the camera vertically which doesn't make much sense. but that is quite normal if trying to run DirectInput games with XInput gamepad, ie. the X-axis of the right analog stick is incorrectly mapped to the analog triggers)

DirectInput mode => the game works perfectly without any fiddling, IIRC including both analog sticks, the D-pad (for selecting e.g. the weapon), and even the color coded action keys in the game match those of the F310 (ie. if it tells you to push a green button, that's what you push on the F310).

It is a bit odd though that there is that color coding in the game, as it does indeed suggest XBox360/XInput support. But in XInput mode, the buttons are mixed. Maybe for the PC version they took the button color coding from the XBox360 version of the game, but still took the controls from the PS3 version, and used DirectInput instead of XInput?

I didn't, since it was working (after the 360CE files) fine. May try it again at some later point though. I know that the gamepad recognition had errors if using anything but a proper 360 controller, but I thought that was the case only with the wireless ones. The fact that this is not the case is interesting though. Will probably have to reinstall and verify it, hopefully later this week.

I've been under the impression that the Logitech F310 in XInput mode works identically with the genuine XBox360 PC gamepad with any game you throw at it. For instance Darksiders, which was claimed to be a "works only with the genuine XBox360 wired gamepad, period" works perfectly with the F310 (XInput mode). I felt those complaints were related to people trying to use their legacy DirectInput gamepads with XInput games, which is certainly iffy in many cases.

But if it really is true that wired XBox360 controller works perfectly with AssCreed PC with default settings and without any additional software (while F310 seems to have some issues specifically in XInput mode (but DirectInput mode works perfectly)), maybe it isn't quite so then? Dang, I want to test it out to get some hard facts and not just assume. Maybe I'll buy a XBox360 wired controller. It never hurts to have a backup gamepad (albeit I'd actually still prefer to buy a second F310 instead :); I won't buy a wireless F710 until Logitech makes one with Unifying support, so that I can use the same wireless USB receiver for it which I am already using for Logitech wireless mice, keyboards and trackballs).

Either way though, at least for me F310 seems to work perfectly with AssCreed in DirectInput mode, without any fiddling. All the controls work (including both analog sticks, the D-pad and triggers), all the controls seem to be mapped into logical places, the color coded buttons are mapped correctly etc. Plug'n'play.

One possible explanation would be that AssCreed still recognizes F310 as a "non-XBox360 gamepad" even in XInput mode, hence offering only DirectInput support for it by default. Ie. like you said, the game would support both DirectInput and XInput for gamepads. It would be the first, I think games usually support only one of them, not both.