Here's my guess
1. FMA.com - (elequa is the owner's username on this forum)
2. UltimateSearch.com
3. Buydomains.com
4. Dotcomcowboy.com
I do think that there's a list of this type already on the dnforum. Run a search to find the list.
+++++++++
Thank you for the vote of confidence, but I will confirm that I am probably not even within the top 100 biggest players for QUANTITY --although I do hold some high quality names. My holdings are 3000 domains. However, I would guess I AM in the top 100 for quality and diversification.
I think BuyDomains is
#1, and UltSearch probably
#2 in terms of sheer numbers.
Saied Yomtobian of Movie Names and CJ Lovik of Dotzup are probably
#3 and
#4 --again in raw volume.
DigiMedia has an extremely high quality collection, but I don't think it is that large. Definitely top 10 for quality.
Eric Borgos of Impulse Communications has approx. 8000 domains, definitely top 100, probably top 50.
Slavik Viner, AKA Viper, as a high quality collection of 4000 names, mostly in adult. Definitely top 50 for quality, maybe top 10.
Rick Schwartz, the 'Domain King' has a 4000 domain portfolio worth mentioning, another very high quality collection which is heavily oriented to adult. It is probably one of the top 10 adult collections in the world, based on quality.
Robert Argyropoulos of Kink.net has 4 or 5 thousand adult domains, top 100 for sure.
These guys have big collections:
Name Administration
Strategist Research
URL Collection
Domain Collection
FMA
How To Internet
John Zuccarini
National A-1 Advertising
Proctor and Gamble
DotCom Agency
Net Income
NUCOM
MicroDomain
Mrs. Jello, LLC
MicroSoft
Yes, I believe DomainGuru may have compiled a list a few years ago.
It would be very interesting to do a new ranking of the biggest players in domains, based on a few different criteria, such as quantity and quality. It would make a fascinating article, and also, potentially a very handy business reference tool.