In no particular order;
Bill Struth, effectively built a football club, our club's tradition, dress code, and honours list would not be half as magnificent if not for him. He won 18 league titles in total, including 14 in 19 years before WWII, at a time when Scotland was as good a league as any other. He revolutionised Scottish football, with attacking football, something Walter Smith would do well to take note of.
Jock Stein, great manager, who won the European cup with a fairly average side, with a few world-class players. They were all born within 40 miles of Parkhead, and it showed his devotion to the game that they all ended up at their local team. He was generally succesful wherever he went, leading Dunfermline to very respectable finishes in the league.
Ottmar Hitzfeld, quality manager, who I love the way his teams play. Had many a notable success, and has a tendency to rise again when his teams fail.
Giovanni Trapattoni, seven Serie A titles, a Bundesliga, whilst playing some fairly pleasing football on the way. I'm amazed he still isn't considered among the top notch Italian coaches, though to be fair, he's up against genuine quality.
Vicente Del Bosque, I love this man; his football is awesome to watch, and he made a team out of the "Galactico's". It could be argued Real Madrid made the biggest mistake in their modern history sacking him, even after two European Cups and two La Liga titles.
Jose Mourinho, the Special one
. I like his arrogance personally, and he is a tactical mastermind, Inter's victory over Barcelona last year was frankly inspiring. Had many a success, including the notable Champions League victory with Porto, and I'm sure he will have many more to come
Alex Ferguson, top quality really what he's achieved. Nurtured 3 generations of Manchester United teams, and had a helluva lot of success along the way. He never looks lost, and always remains calm, even when the chips are down, top quality man.
Arsene Wenger- Worked miracles on a shoestring budget, even if, the shoestring budget was imposed by himself :$ Plays football the right way, it's glorious to watch at times, and is a very keen pupil of the game. Also a very bright man off the field by all accounts.
I also reckon Pep Guardiola could join this lot soon enough, if he keeps it up