My favourite is the Small bumper 3 door big window Mk2 16v in Atlas Grey, awesome car had two of em so far.
Like this?

That was my Mk2 16v GTI, G reg small bumper, 3dr atlas grey. Loved it. Was a great car.
The G60 16v Limited or G60 Syncro would probably get my vote for ultimate Golf, it's just a shame there's so few of them and they are so expensive.
I would probably say the Mk2 16v GTI is the best overall non-limited edition Golf.
The Golfs lost their way with the Mk4, but the Mk5 looks good, has performance to match and has revived the GTI brand.