I find Skyrim's interface to be a pain to use, even more so than that of Dwarf Fortress. In the (admittedly short) time I've spent so far on Skyrim, I think I've spent more time navigating the menus, especially the inventory, than I have actually doing
On the other side of the spectrum of interfaces, I really like TF2's interface. I don't think I've ever had a major problem with TF2's UI, at least after getting into a game (the server browser could be better, but it works for my purposes). In addition to simply looking nice and fitting with the rest of the game's aesthetics (I love the fonts!), it's intuitive and works the way one would expect it to work. Also, as Core said, it doesn't lag (at least most of the time) or waste time with fancy animations.
For example, the team selection dialog:
You can get all the important information from just a glance at this: What each button does, and how many people are on each team. The use of the doors here to represent the teams and the TV to represent spectating contributes to the overall aesthetic of the game without getting in the way of the actual interface. The doors are big, which happens to make them easy to click (the TV's a little harder to click, but it's still big enough to not be a problem). Also, I think
you can use the number keys to choose the option you want, for those who want to get through the interface as quickly as possible or just prefer using the keyboard.
I could write similar stuff about the class selection screen, but it'd be redundant.
The in-game HUD
is also simple and effective, emphasizing the most important information without getting in the way. It also allows extensive customization, which is always a plus, but I've never felt the need to muck around with that.
Somehow, I've grown to like Nethack's interface, in all its ASCII glory. After getting past the pain of memorizing what every single button on your keyboard does (such as W
earing armor and P
utting on rings and amulets being different commands, both separate from removing equipment, which for some reason is bound to A
), it's actually quite efficient in many cases. You could probably say something similar about Dwarf Fortress's interface, but there's a lot more to memorize in that case.