The shirt you're wearing on a football pitch is largely irrelevant. As long as you can distinguish between teams, it really doesn't matter. But that's not the point. Kits can be a thing of beauty, a piece of art, a piece of history. Shirts often become more beautiful when there's a beautiful history attached to them (I support Palace so there's little room for 'beautiful history' so fuck off). This list is my personal list, in no particular order, a mix of nostalgia or personal preference and Adidas.
Crystal Palace Away 1996/97
Maybe my favourite kit of all time, I'm not 100% sure but this is utter filth. Obviously most none-Palace fans wouldn't care as much about this but it is undeniably sensual. The 90's Adidas kits age so well. It's also a carbon copy of France's Euro 1996 away shirt too (with different colours mind), but they only had the likes of Zidane and Desailly wearing theirs, Palace had proper ballers like Neil Shipperley and Ray Houghton. The three stripes down the sleeve, the collar, the sponsor, the sharp white. Oddly enough I can't find a single picture online of this kit being used in a match; Palace were in the second division that season but still odd. Can imagine big David Hopkin looking to curl one in this naughty get up.
Inter Milan Home 1997/98
It is literally impossible for a shirt manufacture to fuck up making an Inter Milan shirt. Blue and black stripes will always bang. This shirt, however, has a collar and collars on shirts get me. Their away kit for that season could have easily made this list (UEFA Cup win in that shirt), but like I said you can't get past the blue and black. Big R9's debut season for Inter too adds that little spice to make this shirt even nicer, especially with that iconic Pirelli sponsor (probably the best shirt sponsor of all time, a proper brand not some betting company or random three letters, think United's AIG or Spurs' AIA, what do those companies even do?)
England Home Euro 96
I've just clocked that all the kits so far are from a 2-3 year window. I guess the 90's knew how to make kits. This shirt is purely iconic. Shearer golden boot winner, spanking the Dutch. Simplicity, like the inter kit, is Umbro's friend here. Highlighted collar and clean pure white. The blue on this kit too adds a nice element not seen on England kits before or really since (much much nicer then those horrible blue stripes on each shoulder on England '08 kit). Again, the away shirt is probably more iconic i.e. Gazza's dentist chair and Southgate's silly little penalty miss but no doubt a fine tournament from England and an equally fine shirt to cry into when it doesn't come home.
AC Milan Home 2003/04
We've finally moved into this century now with this absolutely underrated shirt by AC. Similar to their roommate Inter, the beauty is in the simplicity, black and red stripes. Add to that the iconic Adidas stripes down the sleeves too. Again this isn't a revolutionary kit by any means, but for me simplicity goes a long way. Plus, the team who wore this kit really speaks for itself; this entire description could have just been me listing off some of the names of that 03/04 team and fuck it I'm gonna do it anyway. Maldini, Cafu, Nesta, Pirlo, Gattuso, Rui Costa, Kaka, Seedorf, Shevchenko, Inzaghi (and Rivaldo but he dipped from Milan in November of that season and apparently nearly signed for the mighty Bolton Wanderers)
France World Cup 1998
We started this list with a bit of a mental kit so it seemed reasonable to end it with one (also another kit from 1996-98). Again, half the reason I love this kit is the players who wore it; Henry, Zidane, Vieira. Also it's odd for an non-French person to say, but I love that this kit is just so French, so much rouge, blanc et bleu in this shirt. It's a very bold kit. Adidas had a great take on their traditional iconic sleeve stripes which is echoes across the shirt. And again, I love a collar and this may be the best of the lot. The font choice too for the shirt number and name looks like an NBA jersey font; it oozes 90s culture in the best and most nostalgic way possible. 90's shirts were all baggy and oversized (my favourite kind of shirt) but this one looked to hang over most the the players' elbows. The epitome of retro 90s football all day.