I would raise you with 2009 stock (Victoria Line). The way the designers maximise use of the internal space for maximum passenger-shifting capability really is impressive. It seldom feels like effort to squueze onto a packed train.
That and the smoothness of the ATO acceleration and deceleration.
I'm going to be slightly controversial here and say I prefer the Alstom stock to the 2009 Stock. The reason - I feel that Bombardier got lucky with it as the bodyshell is in effect, a modernized 1992 stock unit with newer traction packages. I also remember when they were first introduced - the issues with the over sensitive door system (which reportedly cost Bombardier over a 1M to fix and was featured in the BBC version of The Tube) and the heat. They're ok, and I prefer them to the S Stock. But 1995/96 stock wins it on the tube for me.
But that's not my choice. Mine isn't the most reliable (unfortunately), but for external and internal designs. Alstom's Class 180 Coradia / Adelante. I love the exterior styling, that very sleek cab which has something almost GWR Railcar about it with the central crease and the streamlined front. The rest of the body is very Metro-Cammel, almost similar to the Class 156. But it's the interior that I still feel impressed by - Large windows, seats which line up with the windows, large luggage racks enough to fit more than a copy of the Daily Mail in, Large Vestibules, 2 Decent Van spaces doubling up for additional luggage or bicycles. The whole units feel bright and airy, the soundproofing is top quality and the ride quality is super smooth. I overheard someone the other day describe them as 'feeling like a cheaper version of the Mk3' - I don't find that insulting at all, because it means that long before we were praising the Mk3, Someone in Alstom and First Group were already working on a design to match it.
Yes it's a shame that the mechanical design wasn't up to scratch, and nor were the Hydrodynamic Braking System, or Alstom's level of support up until the beginning of this decade. But I feel that the Adelante offers something compareable to a HST - And nothing else comes close to it. I really wish the same designers were working on the IEP project now, or Alstom & First Group had got their way in procuring an updated Coradia design.
In a neck and neck race between it and the HST, FGWs HST would just clinch it for it's longevity and reliability. In terms of Modern rolling stock introduced since, the 180 wins it hands down for me.