I've just seen this on Facebook, so thought I'd get the ball rolling on here. I'll just name the first side that comes into my head that I have seen us play! It doesn't have to be League matches, it can include pre-season and Cup matches.
Accrington Stanley
Birmingham City
Cheltenham Town
Doncaster Rovers
Everton
Ferencvaros
Guiseley
Hull City
Ipswich Town
J
Kettering Town
Leicester City
Manchester City
Nuneaton Town
Oxford United
Port Vale
Q
Retford United
Stalybridge Celtic
Torquay United
U
V
Watford
X
York City
Z
Please try to complete the whole alphabet!
Accrington Stanley
Birmingham City
Cheltenham Town
Doncaster Rovers
Everton
Ferencvaros
Guiseley
Hull City
Ipswich Town
J
Kettering Town
Leicester City
Manchester City
Nuneaton Town
Oxford United
Port Vale
Q
Retford United
Stalybridge Celtic
Torquay United
U
V
Watford
X
York City
Z
Please try to complete the whole alphabet!