Kazilla's (Patch 1.11b) Leveling guild!
 

1-15 = Tristram, just join a game and suck exp | finding a exp shrine is highly advised

15-20 = tomb runs, 1 game with a high level running you usually is all you need

20-24 = cows, again 1 to 2 runs and your done, (exp shrine!)

24-25 = ancients... free level take it where you need it.

25-35 = normal baal

35-45 = nightmare baal

45-xx = hell baal

Not only is this guide is easier to read then spectors, and quicker. This guide took me approximately 3 mins to right down. and 5 years of in game testing. tell me im wrong, do it!

(actually its been so long sence i played i might be wrong a little bit, but i know kill mobs in bloodmoor till your level 5 is alot slower then joining 1 trist run : /)

That sounds about right, except you can do normal baal north of your mid 40's and nm baal north of your mid 60's.

This seems pretty common knowledge, I'd like to see some stuff on Chaos and such :)

Actually Kazilla, you don't get decent experience from Nightmare Baal until level 45, and you don't get decent experience from Hell baal until level 65. ;)