Engine oil type?

Hi there I have a '91 1.8 gti cabby
And was wondering what was the best engine oil to use?
Covered 107k

Regards

I have a 1993 Sportline with 163,000 miles on the clock and use Castrol magnetec 10w/40...car is running lovely, but there is also another really good one that VW recommend....I think its Quantem??????I am sure someone else will jump in and correct me :-)

http://www.vwgolfmk1.org.uk/modules.php?name=Forums&file=viewtopic&t=101637&highlight=oil