Many people who don't otherwise use mods much buy wow gold use a bar mod, since Blizzard's default bars are quite limited. Back in the day it was Flexbar or Trinity; nowadays it's usually Bartender or Dominos (but oh, how I miss Flexbar). Dominos is the successor to Bongos, so if you used Bongos in the BC era, you'll probably be at home here, although it's missing a few features that the author found troublesome and not worth it. It's also the bar mod I use on all my characters (along with Autobar, which I'll discuss in a future Spotlight).
The goal of Dominos is to be simple to configure, yet powerful enough for most situations. It also uses the default action bars, so any bars you have set up already in Blizz's interface will port over fairly seamlessly, and things like tooltips work just fine. It also works just fine with vehicles, which are prominently featured in buy wow gold many Wrath quests. Most of the options are hidden away in the bars' individual configuration frames, which are accessible by right-clicking a bar while in config mode (/dom config). A bar can be made as many buttons as you want it, they can go horizontally and vertically, any size you want - all the options you'd expect from a modern bar mod.

Make sure you don't hide your roll frame, though, unless you have a replacement for it; I did this my first time through and couldn't figure out why I wasn't being given the option to roll on items. I also like being able to fade bars when the cursor isn't over them; this is handy especially for class bars on aura-type classes (DK, paladin, hunter) where I change auras only rarely.

Another Dominos feature that I enjoy is being able to bind keys directly to a spell in your spellbook, without having to put that spell on a button. For instance, on my priest and druid, control-R casts buy wow gold Resurrection/Revive. Caveat: this binds to a particular rank, so make sure you re-bind it when you get a new rank of the skill; this issue led to me using rank 2 Binding Heal for quite some time after hitting 80.