Man United's Old Trafford is the closest ground to me at 11.8 miles
Thanks to your question I've just discovered that I actually have 11 league clubs within 30 miles of my front door in Lymm, near Warrington. The other 10 are:
Man City (18.4 miles)
Bury (19.4 miles)
Macclesfield (21.1 miles)
Bolton (22.4 miles)
Wigan Athletic (24.4)
Rochdale (25.5)
Crewe Alex (25.8)
Oldham (26.0)
Liverpool (26.7)
Everton (27.0)
Despite all of this my car still insists on taking the M6 South and the 160 mile round trip to Meadow Lane every other week!