Ice Hockey: I’d want to be a goaltender.
Baseball: 3rd base.
Goalie definitely. I don’t think I’d ever be any good but it looks like a lot of fun.
Baseball: catcher
Basketball: power forward
Hockey: there’s positions?
Football: cornerback
Curling: guy with broom
Football: Cornerback
Soccer: Defensive midfielder
In American football, I’d want to be a nose tackle.
In soccer, goaltender.
In basketball, center.
Soccer: Left midfielder
Rugby: Scrum-half
NFL: Tight end
Baseball: 2nd base
Am. football, punter or kicker only (I don’t relish the aches and pains from a regular position).
Hockey, defenseman with a nasty slap shot and deft passing touch.
Baseball, third base (with training I’m sure I could have gotten my 65 MPH arm up over 80)
But in temperament I’d be better off in an individual sport (auto racing or golf).
Baseball: second base or shortstop
Am. football: pass rusher (assuming I had the body for it of course)
American football - receiver
Shortstop.
A good shortstop is a beautiful thing.
Baseball - Shortstop or Pitcher
Football - Quarterback
Hockey - Right Wing
My favorite team is an NFL franchise. And if I had to play a position on that team? Hm…
Well, I’m a skinny Jewish guy who has never played a day of football in his life. I would probably snap like a dry twig if I were tackled. So I’m going to go with punter. The other team would get penalized for hitting me (in most circumstances), I wouldn’t have the pressure that is put on the kicker, and occasionally, I could throw my body at the legs of the return man, and suddenly I’m the hero who was able to stop him when 10 other (three hundred pound) guys couldn’t.
Yeah, I wouldn’t get the money or glory of a QB or defensive back, but at least when I retire at the age of 53, I wouldn’t have chronic encephalopathy.
[slight hijack]
I may start another thread about this particular thing, but while I’m thinking about it, why on earth is it relevant at all that you are Jewish? Who cares if you are Jewish?
[/slight hijack]
<snip>
You’d still be jewish. 
Outside of Sandy Koufax, name one decent Jewish athlete. Exactly. 
Ice hockey-right wing
In my fantasies – begun in childhood and never quite given up on – I have always been a left fielder for the Dodgers.
Sadly, in real life, while I still have some speed and catching ability and can even scale a wall decently at my age and weight, I’ve never been able to throw for any distance without making it a rainbow.
My first though was center fielder. When you think of graceful players, you usually think of center fielders like Willie Mays and Joe DiMaggio. But then I decided I’d rather be a third baseman. There’s something just cool looking about charging a bunt or making a backhanded stab.
Second base.
Football, obviously – there aren’t any other sports:
Assuming there was some body-morphing technology that would actually allow me to play, I’d be a defensive end. One job: get off the snap quickly and kill that bastard with the ball.
Ryan Braun, the Hebrew Hammer (a nickname also apparently applied to Gabe Kapler, Hank Greenberg, and Al Rosen). 
Back to the original question…
Football: tight end, or placekicker.