In some of the stories characters crossover
JUSTICE SOCIETY OF AMERICA
Captain America - CHRIS PINE
The Flash - HARRISON FORD
Sentinel - KEVIN COSTNER
Wonder Woman - LYNDA CARTER
Dr Fate - DANIEL DAY-LEWIS
Dr Mid-Nite - JIM CAVIZEL
AVENGERS LEAGUE
Captain America - CHRIS PINE
Martian Manhunter - TAYE DIGGS
Batman - BEN McKENZIE
Wonder Woman - MEGAN FOX
The Flash - ADRIEN BRODY
Green Lantern - NATHAN FILLON
Iron Man - ROB LOWE
Thor - SAM WORTHINGTON
Captain Marvel - PATRICK WARBURTON/ALEX PETTYFER
Aquaman - ARMIE HAMMER
Amander Waller - ANGELA BASSETT
THE AMAZING SPIDER-MAN
Spider-Man - MICHAEL CERA
Mary Jane Watson - EMMA STONE
J. Jonah Jameson - ED ASNER
Lois Lane - NATALIE PORTMAN
Perry White - HUGH LAURIE
Jimmy Olsen - ANTON YELCHIN
X-MEN
Superman - JON HAMM
Phoenix - ISLA FISHER
Beast - KIEFER SUTHERLAND
Angel - JOSH HARTNETT
Wolverine - GERARD BUTLER
Lex - BILLY ZANE
Jor-El - CLIVE OWEN
Professor X - TERRY O'QUINN
Jonathan Kent - ROBERT REDFORD
Martha Kent - SALLY FIELD
Braniac - JAMES MARSTERS
General Zod - KARL URBAN
------------------------------------------------------------------------
So here is my pick of essential stories from the site:
1. Crisis on Merging Earths
2. War of the Worlds
3. JSA: In The Beginning
4. The Shadow/Doc Sabvage: World's Finest
5. Detective Comics: Birth of the Batman
6. Batman: Trials & Triumph
7. The Amazing Spider-Man
8. Batman/Spider-Man: The Sinister Six
9. X-Men: Registration
10. Avengers League: The Return
11. Return of the Sinister Six
12. JLA: Green Legend Rises
13. Ultimate Crisis