I have a pretty solid collection of EDH cards that I've built up over the years. My principal for collecting is to only buy and use cards that are worth $5 or less, which keeps the hobby from becoming expensive and the collection fairly diverse.
What's funny is that after all these years of acquiring interesting crap rares the number of white cards I own for EDH is abysmal compared to the other colours. The white pile is a sliver at the back of the box, and honestly I'd guess 70% of the cards I own in white I've never used and probably never will.
White is simply not a fun colour. The closest it gets is when paired with red for something like basandra or master warcraft. White's contribution to the format can pretty much be boiled down to this:
Disenchants: Return to Dust, Ray of Distortion
Wraths: Akroma's Vengeance, Austere Command, Hallowed Burial
Point removal: swords to plowshares, condemn
Tokens: sacred mesa etc
Angel fat: Akroma, Adarkar Valkyrie, Angel of Despair
Land fetch: land tax, wayfarer, tithe
(if you're cheese loving, add karmic guide and reveillark for combo cheese I suppose)
The sad thing is green gives you comparably good disenchants (stomphowler, krosan grip, acidic slime), tokens, fat, and better land fetch. Black gives you comparable wraths and point removal. And meanwhile black and green have all kinds of interesting crap rares to give your deck that extra oomph.
I actually combed through my collection to see what white cards I have that I'd consider interesting for EDH; there are 14 and that's being liberal with the definition of "interesting":
Patron of the Kitsune
Konda, Lord of Eigango
debt of loyalty
reverse the sands
autocthon wurm, hunting grounds, akroma, wraths), Cromat (Nephilim...) and Teneb (wraths).