Definitely grab At Carnegie Hall, Brubeck And Rushing, Time Further Out, Time Out, and Gone with the Wind (those are my personal top five in order from 1 to 5).
I agree on "Carnegie Hall", "Time Out" and "Time Further Out", but would throw in "Jazz Impressions of Japan" as a top choice, and "Brubeck Time", which includes Paul Desmond's delightful tribute to/impression of "Audrey" (Hepburn of course).
Either way, it's hard to go wrong with Brubeck's classic quartet with Desmond - the main question is: how much of it do you need? If you want a lot, grab the box with the complete Columbia Studio Albums - it's curretnly down to 40€ on aDE:
https://www.amazon.de/Complete-Columbia-Studio-Albums-Collection/dp/B0077PPQGO/There's of course more to Brubeck than that ... the early Fantasy recordings with Desmond are glorious, there's some trio, solo and octet music as well (some of it pretty ... let's call it "academic"), and there are a few quartet recordings with clarinetist Bill Smith in place of Desmond (of which "Brubeck à la Mode" may be the finest?). There is also one with Dave van Kriedt (a sideman from early days) added to the quartet, which is fine, "Re-Union".
In addition to these Fantasy recordings, there's some more good music on Columbia, including the live albums not covered in teh box, and then the one with Gerry Mulligan following Desmond - alas not easy to find. On Atlantic then, there's one with Desmond and Mulligan that was, I think, my very first Brubeck (it's part of my dad's record collection), and it's pretty good and lots of fun, "Together Again for the First Time". There's also a rather odd one with Anthony Braxton and Lee Konitz (one track in common, Konitz on two more, Braxton one one), "All The Things You Are". Either way, Brubeck gets slammed unfairly quite often in jazz circles ... I don't want to be part of those that do so!