Oh, I love the alt- and else-beginnings... second When Larry Met Charlie. Field of Dreams is great -- WAFFy but not shallow, if that makes sense.
Okay, in the elseworlds category (the Pilot never happened or is re-written):
Sheila Harper's
In the Beginning B.B.Medos'
In the Beginning Four Days to Nightfall by Nan Smith
Master of Disguise by BJ
Between Floors 7 and 8 by Jessi Mounts
Possibly my very most favorite two:
The Girl Next Door by Janet Owens
Stardust by Caroline K
And when you're tired of reading about Dr. Platt
... Alt-Clark stories:
In the Bleak Midwinter by Wendy Richards
Then Came You by Jeff Brogden.
How I Spent My Christmas Vacation by Nan Smith
Long Strange Trip by L
...and in the Shameless Self-Promotion department, I'll also mention two I wrote:
Hearts Divided (elseworld)
My Interview with Superman (alt-universe) (short, but w/four sequels)
I know I'm missing some but that's a good start. For more fan favorites, check out the
Kerth Awards -- most years there's a Best Elseworlds, Best Alt-Universe or combined category, and stories don't even get nominated to the Kerths unless they're pretty darn good.
PJ
ps., thank you BJ for mentioning Tryst!