T-shirt design suggestions for an event?

Sounds like a fun event! How about something like this:

10th Annual Snowbowl 2014
<Insert whatever picture/logo you choose here>
We came, we flagged, we conquered.

“I’ve been playing flag football for ten years and all I’ve got is this lousy T-shirt.”

Snowbowl…much more fun than a rosé bowl.

Snowbowl…it’s so much more than just a bowl full of snow.

Reach for the Sky or don’t even try.
Defend till the End.
We Don’t Make Excuses… We Make Plays.

I agree with @augustlan that it’s gotta have 10th Annual Snowbowl 2014 above the graphic and a catchy tag-line below.

How about “Snowbowl Play-Maker, Can I Make a Play for You?

10th Annual SNOW BOWL!
(logo of snowman with Vince Lombardi trophy made of snow)
Come have a ball while we freeze ours off.

I was thinking along the lines of snowmen too, but instead of one, a team, maybe in huddle. If any of your players have noteable characteristics such as a favorite hat, sweatbands, mutton chops, just enough of those traits to make the snowmen recognizable.
2014 TEN YEARS OF
Great Guys
Great Plays
Great Chili

To expound on @Buttonstc ‘s idea:
10th Annual Snowbowl 2014
“Not just a bowl of snow”.

Picture of Edward Snowden playing tag football.

10th Annual Snow den Bowl
Making plays for the greater good.
(In one of these fonts.)

Ten Years
One Game
10th Annual
SNOWBOWL 2013!!

design a helmet that looks like a bowling ball with a snow cone on top of it.