The problem of putting Robbo in lists of all time great players, is that his trophy cabinet is virtually empty. And that is a big concern, and a reason why he is almost completely unknown outside of UK. Being a great player in England's tenth or so best club (which is what United was back then) can make a player a legend of his club, but not a legend of the sport.
Unfair? Probably yes. But it is also something that we like to mention when we argue Scholes vs Gerrard. And well, Gerrard has won more than Robbo.
Robbo's trophy cabinet isn't really that bad:
Manchester United[edit]
Premier League (2): 1992–93, 1993–94
FA Cup (3): 1982–83, 1984–85, 1989–90
Football League Cup (1): 1991–92
FA Charity Shield (3): 1983, 1990 (shared), 1993
European Cup Winners' Cup (1): 1990–91
European Super Cup (1): 1991
He was somewhat peripheral to the league wins granted, but it still compares favourably to someone like Socrates who has been mentioned in this thread and is generally seen as a great:
Botafogo-SP
Torneio Vicente Feola: 1976
Taça Cidade de São Paulo (first stage of Campeonato Paulista): 1977
Corinthians
Campeonato Paulista first stage winner: 1978, 1982
Campeonato Paulista: 1979, 1982, 1983
Flamengo
Taça Rio: 1986
Campeonato Carioca: 1986
Brazil
Copa América: Runner-up 1983; Third-place 1979
I did consider it, but for me Nedved is a far far better player than Giggs and has more in his arsenal. One of my all time favourite players and I need to have him in my team. In this team his versatility is more useful than his pure width (which he is capable of btw).
I think 'far far better' is very harsh on Giggs. Giggs had his poor seasons across his mentally long career, but at his best he was an absolute machine in terms of chance creation. I think he's actually become underrated with the passing of time.