Working approximately South to North in UK:
Porstmouth - a number of matches when I was living down there
Fulham - a few league games against Spurs
Chelsea - a few Spurs games
Arsenal (Highbury) - numerous games
Arsenal (Emirates) - just one, so far
Spurs - countless
Wembley (old stadium) - three Spurs FA Cup finals, one Spurs League Cup Final, a couple of Amateur Cup finals back in the 1950s, numerous England internationals, including a 9-3 win against Scotland, and a 4-2 win against West Germany
Barnet - about four times, the first being when they were still in the old Athenian League in the FA Cup against a Preston team which included a very young Howard Kendell.
Watford - most memorable was seeing them put Liverpool (Ron Yeates and co) out of the FA Cup
Birmingham - one cup game against Spurs
Aston Villa - one cup game against Spurs, and one which I watched from the directors' box
West Brom - one game against Spurs
Leicester - just once, against Spurs
Nottingham Forest - a few, against Spurs
Notts County - twice, my first two games (Tommy Lawton played in the second)
Stoke City (Victoria Ground) - numerous
Stoke City (Britannia Stadium) - about three times
Port Vale - a couple, including Spurs' defeat in FA Cup
Crewe Alex - just one, I think
Sheffield United - just once, against Spurs
Sheffield Wednesday - just once, Forest v Spurs FACup semi (1967)
Leeds - just once
Bradford Park Avenue - fourth div game against Workington Town
Bradford City - three or four games
Manchester United - three times, in all cases, the team I was supporting (Spurs twice, and Barnet once) got beaten 4 - 1. One of those was European Cup Winners Cup.
Liverpool - just once - they scored seven against Spurs (first time I saw Ardeles)
Sunderland (Roker Park) - just once
Hamden Park - a few Scotland internationals, a couple of Rangers v Celtic Cup Finals, and a Queens Park league match
Ibrox Park - many times
Celtic Park - many times - including all of the home games when Celtic won the European Cup
Partick Thistle - once
Hearts - once
Hibs - once
UK non-league grounds
Enfield - once
Alsager Town - numerous
Newcastle Town - a couple
Congleton Town - once
Maine Road - twice (that's Maine Road FC, and not the old Man City ground)
Ashton Athletic - twice
Abroad
Ajax - their old stadium (1950s)
Some bigger stadium in Amsterdam to see friendly between Ajax and Barcelona
Nou Camp - once
Stade de France in Paris- once
I don't think I've missed any.
Best of all has to be Nou Camp. Fantastic stadium. Fantastic atmosphere.
The strangest ever has to be Hamden Park, when I saw Queens Park in a league game. Capacity in those days was around 120,000, and the gate was about 100. I parked my car right outside the only turnstile which was in operation that evening.