Basically what I'm trying to create is a scoreboard type thing, with people's usernames (withwho in the table) and have it ordered by the number of rows in the database where withwho is their name.
Here's my non-working query

SELECT DISTINCT withwho FROM game_listing ORDER BY COUNT(withwho) DESC

Please help, or if you need more info I'll provide a prompt response - thankyou.

Try something like:

SELECT DISTINCT withwho, COUNT(*) AS count FROM game_listing ORDER BY count DESC

I tried, no luck, mysql_error says:
Warning: mysql_numrows(): supplied argument is not a valid MySQL result resource in /home/sites/tbhg.co.uk/public_html/leagues.php on line 222
Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause

So I turned the ORDER BY into a GROUP BY but:
Can't group on 'count'

Anymore suggestions?

SELECT withwho, COUNT(*) AS count FROM game_listing GROUP BY withwho ORDER BY count DESC

Fantastic work sir, it works perfectly and has taught me something I can use in future - cheers mate!