If it helps, I'll list mine, which I've been using for the entire game without too much trouble, aside from the afore-mentioned targeting issues that happen when living seeker projectiles of any sort are around.
Fairly simple setup, using a PS3 controller, should be adaptable to a 360 one just fine I should think.
Dpad for movement. You can also set the Dpad to handle menus, there's a command in there somewhere.
Start for pause, Select for dropping either a Light Orb or Moon Lamp, depending on if I have Moon Lamps; if I have the Flash of Light spell at least at level 3, it is set to fire that instead. So Select is the "light" button.
X jumps, Square for confirm/interact/enter door, triangle is always to set platforms (which tend to appear just above the character, works out well), and circle either drops a crate, drops a bear trap, or uses Light Snake, depending on the situation/area.
L3 (pushing left stick in) cancels target, R3 (pushing right stick in) switches/sets target.
The four shoulder buttons are for spells, wether they be attack spells, defensive things like shields, or utility types. Switched out depending on situation/area.
The right stick is still capable of aiming if need be, but I never seem to have to do this.
This so far has been a pretty good setup (and I'm playing on a high difficulty), and I've been playing the game for some time now, so have had alot of time to experiment with it and tweak it.
There are only a couple of downsides:
1. Yes, you still have to use the mouse to move inventory stuff around or change enchants. There is a way around this though, I'll get to that in a moment.
2. The targeting system is pretty great, actually, BUT, it means that all your attacks will fire DIRECTLY at the target; they wont lead the target or something like that. The two "rock" spells..... the normal green rock and the ice brick, whatever they're called, wont hit their target. Slow-moving spells like Tidal Pulse or Creeping Death can be a little tough to use. That being said, they're still totally usable; Tidal Pulse is one of my favorites, and I really have no trouble hitting enemies with it, even with the targeting, I just have to change how I approach it. Just takes some practice.
3. Storm Dash is..... sensitive. As you'd expect this activates simply by pushing forward twice; well, the dPad can be a little oversensitive, and it's easy to fire this off when you DONT want to. In particular, the 360's dpad is a complete nightmare (seriously, they dont GET worse than that. As a shmup fan, I've had PLENTY of time to prove this). You can of course choose to use the left analog for movement if you want though; I just stick with the dpad anyway.
Now, as for the mouse bit, look for a program called JoyToKey. This is what I use to make damn near every game I play on PC work with a gamepad/controller, wether it wants to or not. It can actually be used to convert controller input into mouse movements/actions (among the many other things it can do). I use this for Minecraft, so I can handle inventory/hotbar without ever having to so much as LOOK at the damn mouse. Set one of the sticks to mouse use.... might take some experimenting, but JtK is fairly easy to use and figure out. Do feel free to ask if you have a question about it. But that's how to make THAT happen. You would need to have a free button available to set to the actual left click function though, so keep that in mind.
Yeesh, hope that wasnt too much to take in all at once. Hope it's somewhat helpful at least.