Favorite grouppo due to pure nostalgia would be Super Record, hands down. For performance in the older stuff, my fave to this day is Superbe and Superbe Pro.

That said, I far prefer Ergo shifting and dual pivot brakes from a practical and performance standpoint, so I'm with Gomango on the Ergo 8/9, as I still consider it to be in the "classic" category, and it is about to become "vintage" (it has been 20 years since it was introduced). Once I tried Ergo, Downtube friction shifting suddenly became a quaint nostalgic memory, like Cambio Corsa.