To me it would actually be easier to say who doesn’t sound dated. Certainly to me most ‘classic rock’ sounds very dated, in fact it almost has to be by definition of being 'classic', but that’s not remotely a criticism, there’s nothing wrong with liking music which sounds dated, I actually like dated things, that’s why I love classic rock instead of all this modern crap. Saying something sounds dated is actually a compliment and something to be proud of when you look at all the horrendous modern alternatives (rap, most hiphop, poppy R&B)...in fact we should rejoice in our datedness!!
But for example, stripped down to their basics, did the most recent AC/DC or Van Halen or Aerosmith or Iron Maiden or Deep Purple or Lynyrd Skynyrd albums actually sound any different to the first albums these bands recorded 35-40 years ago? No, of course they don’t, in fact stylistically they are almost carbon copies, unless anyone is willing to try and convince me that ‘Black Ice’ (2008) is a dramatic departure from ‘Back in Black (1980)?? These bands don’t display any real originality, or ever do anything new or truly experimental, they just stick with the same basic sound/formula which made them popular in the first place…but then that’s exactly what we, their audience, demands, which I guess means that our expectations as listeners are also equally dated.
If the opposite of sounding ‘dated’ is sounding ‘modern and fresh and original’ …. then it’s actually difficult to think of hardly any bands that I like off the top of my head whose sound ever evolves and changes much at all…though to my ears Radiohead are one band who do, love them or loathe them, each Radiohead album is virtually unrecognisable from its predecessor, in fact they maybe even try too hard to do something radically different, and also Rush to me are always looking to try and find new things, and their style to me never sounds dated or jaded, and each new Rush album sounds fresh, though at the same time it's still instantly recognisable.