Global Agenda, for instance, an otherwise pretty decent mmo/rpg/tps/thing.
Lets start with the equipment screen, as it's generally one of the more used menus in the game - along the bottom you have a list of categories and item slots that belong to the currently selected category.
To the right you have a list of available items that can be equipped in the current slot.
For some reason, the developers have decided it's a good idea to only display item stats when the mouse cursor is hovering over the icon of an item. At the very least the tooltip could have been displayed when the cursor was over any part of the item's inventory listing and not just the icon.
But that's tackling the problem from the wrong angle, what would have been a much better solution would have been to display the important stats in the inventory listing, rather than the tooltip, so that you can quickly and easily compare the various items you have at your disposal.
I don't think "Generation 1" is particularly important information to know at-a-glance (and "Assault boosts" is just plain redundant information, since I know that I have selected the "Boost" item slot and that my character is an agent of the Assault class).
You'll notice a little spanner icon beneath some of the item slots, this is how modifications are applied. I had to seek help when I first wanted to install a weapon mod because I couldn't for the life of me figure out how to do it. Surely I should be able to click on a mod in my inventory and select "apply to slot x" from a drop down list or something similar? Nope, I must click this tiny little button, select "modify" (the other option being to repair a damaged item) and then find the item I want from a secondary inventory view.
Buying and selling in the NPC shops doesn't fare any better. Immediately you'll notice that there is a difference in how the items are displayed between your inventory and the shop's.
It's actually quite hard figuring out which items of yours you want to sell, given that you have to hover the cursor over the icons to see what it does. The only information you are given at-a-glance is the colour of the text, which indicates how rare the item is.
There is no value listed with an item in your inventory (even if you hover the cursor over the icon), you have to click the sell button to see how much you'll get for it.
A lot of the items you receive whilst playing the game have no function in and of themselves and are just building blocks for crafting items, unfortunately there's no way of telling if these components are something you want to keep when you're at this screen.
Though having said that I'm not sure if many games provide you that kind of information when you're at a shop about to sell them, so it might be asking a bit much - but it's definitely the kind of feature that should be considered when implementing a crafting system into a game.
The auction house is another example of just how little information the UI gives you.
When you first open it up you are presented with a blank screen. If you attempt to search for something, you are told to first select a category. Of course, that by itself isn't enough: you must select a category and then hit search to actually display anything at all.
Which seems backwards to me, the auction should by default display all things currently for sale (or at least the first page or so). The category listings on the left should then be used to filter the items on auction and then, if you so require it, you can use the search to narrow it down further - with or without a category selected, who's to say you know which category the item you have in mind belongs to?
It's also very unclear as to how bidding actually works - surely the developers have seen ebay? That's a great source of inspiration when looking to develop some kind of in-game auction system!
Like I said at the beginning of this post, the game itself is perfectly fine, it's just got a horrendous menu system that clearly wasn't given the attention it deserved during development.