There are a lot of websites out there that post memory records. One of the best and most comprehensive websites is http://www.recordholders.org/en/list/memory.html
From what I can see this website is updated very quickly and seems to be very accurate. For those who train very hard to set memory records, it is important that these records are accurate for the world to see. This is one of the best websites that holds all the information.
For example, here are the postings on the most words memorized in 15 minutes
Memorisation of Random Words (15 Minutes)
Random words are presented in columns of 25 words. Scoring is tabulated by column: one point for each word. However, one mistake reduces the score for that column by half, the second mistake reduces the score for that column to zero.
125 | Dominic O’Brien (Great Britain) | 1993 |
153 | Dominic O’Brien (Great Britain) | 1995 |
155 | Dominic O’Brien (Great Britain) | 1997 |
174 | Andi Bell (Great Britain) | 1998 |
182 | Andi Bell (Great Britain) | 2002 |
199 | Boris-Nikolai Konrad (Germany) | 2004 |
214 | Boris-Nikolai Konrad (Germany) | 2006 |
227 | Boris-Nikolai Konrad (Germany) | 2007 |
255 | Boris-Nikolai Konrad (Germany) | 2008 |
280 | Boris-Nikolai Konrad (Germany) | 2009 |
300 | Simon Reinhard (Germany) | 2010 |