Without a doubt the best resource I found for funny best man toasts was Dan Steven's best man speeches .
It's not free but taking into consideration the amount of time you will save searching through yesteryear's wedding toasts and painfully unoriginal cliches on the net, and the amount of pressure it takes off then the 20$ (or whatever it costs now) is well worth it!
Really saved me big time when I was in a tight spot.
There are many speeches to work from and a solid structure to which you can add and personalize as much or as little as you want. My best man speech took me about an hour (max.) to prepare.
The speech / toast sounded very professional and was well appreciated. I was very happy with the day and wouldn't change anything about my preparations.
Hope that can help you a little,
all the best.
