vBulletin is an awesome program on the front-end, but the back end is very duct-taped together and uses very poor coding practice.

Uhh! As a professional coder (who has been very highly experienced in vbulletin modifications), I can't disagree more. Vbulletin code is very elegantly put together. As a matter of fact it is a masterpiece (no I'm not in vb dev team). I can agree with you regarding vb2.x to a certain extent but 3.x is very nicely coded.

Back to subject: It is vbulletin for me because it is more advanced on its features and has the best hacking community in which you can find thousands of free modifications and add-ons for your board.