What is the best groupset over the past 25 years (1998-2023) in your opinion?

[Canuk]

Yep, 7800 triple version with long cage rd. Works a treat and can take big ratios in its stride. Don't bugger up the rear derailleur though, cos they cost...!

 

[peetee]

7800 for me. I managed to bags a few groupsets when they could be bought for decent money. Now people are asking 50% more for them.
6600 comes a close second, especially the blue-grey SL version which looks gorgeous. 4600 Tiagra is good too. I prefer the shift on these over Dura-Ace as they are a tiny bit more weighted so it’s less easy to accidentally double shift.
I want to like Campagnolo but, to be frank, it’s been pig ugly for years.

 

[pigman]

Yep, 7800 triple version with long cage rd. Works a treat and can take big ratios in its stride. Don't bugger up the rear derailleur though, cos they cost...!

I managed 50/34 and 12/30 on a standard 7800 rear mech

 

[bikeworkshop]

I managed 50/34 and 12/30 on a standard 7800 rear mech

The parallelogram is usually the same on short and long cage dérailleurs, but the total capacity is different.
Shimano says max rear sprocket is 27, but in fact they handle a 30 no problem.

Here You'll need a capacity of 16+18=34.
Short cage SS gives 29, so you'd either get too tight or baggy, or both.
Obviously you can apply discipline to gear choices, but it's incompatibility is clear.

Long cage GS hss a capacity of 36, so this ratio will be fine - although careful choice is needed on the inner front sprocket so the teeth align with a shifting chain correctly.