... And It's All Going to CHARITY

Just when you wanted to hate the guy for winning $50,000 on a freak Super Bowl bet -- Giants fan Jona Rechnitz tells TMZ, he's donating every last cent to multiple charities ... INCLUDING one of Tom Brady's choice.

In case you didn't know, Jona -- who runs a successful real estate company in New York -- hit the JACKPOT yesterday, betting $1,000 on the Giants to score the first points in the big game with a safety. The odds were 50 to 1.

Jona tells us, he plans to donate $5,000 to Tom's charity of choice -- in the hopes Tom and the Pats will match it -- and $5,000 to the charities of choice for the Giants defensive linemen who made the safety play. Jona also wants to take Tom out for an all-expenses-paid falafel dinner.

As for the rest, Jona says he plans to divide up the balance after taxes ... and donate it to a bunch of charities benefiting the less fortunate.