As a Yank, and an older one, I go back to the clubs I remember hearing about when I was young and thought of as "big", and then add a few I have a soft spot for, and then add the American perspective which means I don't like them but want to beat them:
City
Yankees-in-Red
The team Americans like "because the Beatles came from there"
Wolves (my first uni as tot playing was old gold and black)
Newcastle (iconic)
Villa (iconic)
Leeds (iconic and remind Americans of the deep south)
Arsenal (typical American: "In London, cool logo")
Spurs (typical American: "In London, named after American basketball team")
Norwich (my soft spot)
Southampton (iconic)
Coventry City (" . . . have never won the FA Cup.")
Palace (my son's side)
Blackpool (Stanley Matthews)
Forest (Brian Clough)
Brighton & Hove Albion (my daughter's side)
PNE (not sure why -- just been a long while since they've been good)
Bradford City (I want them to beat Leeds; in memory of the fire they deserve success)
Brentford (a London club without a stick up its ass -- can't be Fulham after that statue they should be forever cursed)
QPR (every league needs a doormat)