III is your fave, huh? Interesting choice. They began doing the whole 'Alistair Crowley' black magic sound then. It's a great album but I'd say 1 could be my fave.
The only good song on Presence is Achilles Last Stand. It's in my top 5 Zep songs.
Coda is good because they picked the best of what was left over after Bonham died, from what I know. There wasn't much left, however.