“May all your ups and downs be between the sheets.”
This struck us as the height of wit at high school keggers.
A visual gag toast, generally used on close friends:
<hold up your glass>
“Here’s to X…” where X is the man of the hour
<sip from glass, turn head to one side, and spit it back out on floor>
“Ya prick.”
Works best when you coordinate the gag ahead of time, so everybody but the mark spits.
A wedding toast that I read somewhere and I’m dying to use:
When you look back on this day, may you discover that it was the one day in your marriage that you loved each other least.
Well, my dearest gal pal has what I consider a show-stopper of a toast, although she only delivers it when not in mixed company.
WARNING: THE FOLLOWING TOAST IS A BIT RAUNCHY.
Read at your own risk. 
*"Eat me, beat me, bite me, blow me
Suck me, fuck me, very slowly
If you kiss me, don’t be hasty
Use your tongue and make it tasty."*
Everyone’s always very eager to toast to that, I find. 
This is fantastic. I’m to be the best man at my father’s wedding in a couple weeks (pressure? yeah, a little), and I think I’m going to use several of the less raunchy of these.
Aw, elbows, I was gonna put that! There’s another Irish one like that:
‘As you slide down the banisters of life, may the splinters never point the wrong way’
I think my dad used that at a friend’s wedding, he’s been best man for a lot of people.
In John D. McDonald’s book The Walking Drum, which is set in the 15th century, there are a group of people of another country (don’t remember what country, been years and years since I’ve read the book), who use the toast: “Yol Bolsun” which translates to: “May there be a road”.
I’ve always found it to be simple, yet complex in its implications. I like it. Unfortunately, I only get to use it (in the original languange) with my husband (who read the book right before I did), because no one else knows what it means.
A funny one from RenFaire gatherings:
“To Scotland, where men are men and sheep are nervous!”
To all the kisses I’ve snatched and vice versa.
When my 18 year-old nephew married his 16 year-old girlfriend, the guests were actually making bets on how long it would last.
It fell to the best man (the groom’s older brother) to try and toast the couple to a happy send off.
“Well, they did it, just like they said they would.”
The book was written by Louis L’Amour, not McDonald. I loved it as a kid but find it kind of cheesy now. In any case, Yol Bolsun is a great toast. I used to use it as a closing back in the day when I used to write actual letters.
The best man at my wedding used a phrase from the beginning of a song that I liked (which I can’t for the life of me remember the name of now):
“Love blossoms like a lotus in a concrete sidewalk.”
I just love the image that it brings to my mind and what it means to me.
To honor
To having honor
To keeping honor
To staying on her.
My favorite:
“Here’s to panties: They’re not the best thing in the world, but they’re damn close to it.”
I need a beer.
Heres to the duck who swam in the lake,
Who fed his mother by mistake.
Now you might think that fking’s a sin
But it’s been around since time began.
Adam f*ed Eve, and she is our mother,
So we were put on this earth to fk one another.
Drink!
My personal favorite is useful on any number of occasions.
Montrose’s Toast:
He either fears his fate to much,
or his rewards are small.
Who dare not put it to the touch,
to win or lose it all.
Perhaps more of a “bachelor party” than wedding toast…
Here’s to the women in their little red shoes
They’ll spend our money and they’ll drink our booze
They may have their cherry, but that’s not any sin
'cause they still have the box that the cherry came in
Friends may come and friends may go
Friends may peter out, you know
But I will always be your friend
Peter out or peter in
The Tiler’s Toast…
To all our Brothers around the world,
here is wishing them a safe return to their homes and families
If that be what they wish.
Usually given at the New Years Day dinner in a Masonic Lodge.
… oh.
(leaves, disappointed)
Here’s a couple (not mine, but I’ve used them on occaision):
Here’s to the ships of our Navy,
And to the women of our land!
May the former be well rigged,
And the latter be well manned!
and
Here’s to the game of ten-toes,
It’s played all over town,
The girls all play with ten toes up,
The boys, with ten toes down.