I only have mk5 experience with shocks, although essentially the same please don't count this as gospel...
So assuming you want a stock ride height just shocker replacement for use with std springs,I rate the Bilstein B4 as an oe replacement, had them on my ed30, but if i was buying again it would be the monotube Bilstein B6, especially after recently trying them on a friends car.
Imo far better than std shocks, firmer than stock, bit like acc sport mode with 19" wheels but without the clanky feel and noises , also not as bouncy, firmer but quieter and in a funny way more comfortable than stock as they absorb bigger bumps better.
I can only imagine on a mk6 they would be even better ,being as the mk6 versions are apparently valved slightly softer.
Hope this helps