Tough to narrow it down to 5, but I've gone with
Ederson - Perfect for our system, capable of making big saves too. Cost half as much as Kepa and Alisson.
Gundogan - 20 million an absolute bargain, this seasons performances get him higher up the list.
Bernardo - 43 million was a steal at the time and he dragged us to the league title in 2018/19.
Jesus - 27 million, an incredible deal. A key part of our attack in the centurions season in particular, his numbers are fantastic. New contract needed ASAP.
Laporte - 12 months ago he would have been at the top of this list with Eddie, but he's struggled for fitness and form. Still, a world class player and a very good signing, considering we almost ended up with Jonny Evans. Another one crucial to 2018/19's success.
Honourable mention: Walker - Despite his limitations he has been crucial to this side since arriving, and was almost certainly the best all round right back in Europe for a period. The best player we could have possibly got, so kudos to Txiki for paying the money when others would have baulked.
Only reason I've not gone for Dias is because he hasn't won anything yet. Sane doesn't make it because we should have got 100m more for him, unfortunately.