Where can someone get a list of all the ethereum accounts and sort it by the # of ether they have?
The most convenient way to get his information presently is via etherscan blockchain explorer:
Currently, it shows that top 5 accounts are:
Poloniex Cold Wallet (7.8 million Ether)
Kraken (2.2 million Ether)
EthDev (1.75 million - this is a multi signature contract)
0x1937c5c515057553ccbd46d5866455ce66290284 (1 million Ether). This one has bought Ether at pre-sale and has not spent any of it yet
0xd12cd8a37f074e7eafae618c986ff825666198bd (almost 1 million Ether). This one accumulated it over the period of 170 days (withdrawn from Poloniex Hot Wallet)
This is not accounting for people holding multiple accounts. Below is the first 3 pages of the list.