Discord. I'll have to check that one.
Most people swear by CT_Mod, but I had bad experiences with it early on, and fell back to the basic UI control. I added Sidebar, a mod that was there before the basic UI allowed sidebars, but I still like it better.
So, with my Warlock (probably the most button-intensive class, or close to it), my UI has the main buttons on the bottom, hotkeyed to spells, and then the bottom bar right above it is full of more spells, all hotkeyed to my number pad. Then I have a sidebar for my pet and demon-type spells, a couple of which are hotkeyed to some F keys for quick pet summons or pet heals.
All told, while running through the game just fighting normally, I'm working off like 28 hotkeys, all represented by buttons on-screen, with another row of 12 buttons for eating and drinking and utility. But, I still have good real estate on the screen to play the game. All without using CT_Mod or any other UI mod addon other than the very basic Sidebar mod. For my down-time buttons, like enchanting, cooking, tailoring, I shelve those in one of the alternate bar sets, and do shift-mouseroll or shift-# to pull them up when in cities.
Other mods I use and cannot do without are the Calendar Mod (I found this one for my guild, and they LOVE it -- we scheduled and ran Uldaman off it last night); Auctioneer/Enchantrix; and Atlas. Another program I cannot do without in Cartographe, which is a 3rd-party searchable world map, and runs outside of WoW. I'm always alt-tabbing over to search it for the mobs or items I need for questing.
All in all, the best place to go look for mods is probably
www.worldofwar.net -- the boast having recently logged the uber-millionth mod or something like that. Their top 20 list usually has most of the mods/addons I mentioned here, so check it out.
[ 12-30-2005, 10:29 AM: Message edited by: Timber Loftis ]