I think Walt Simonson's Thor and Orion both live up to the hype.
Grant Morrison's Justice League and All Star Superman
Kingdom Come
Englehart and Rodgers Batman
Astro City by Kurt Busiek,,,, especially the Jack in the Box run and the one with the steel plated detective/noir.
Planetary, Stormwatch, and the Authority by Warren Ellis
+1
To this I'd add Star Wars: The Last Jedi. I enjoyed it a lot (except for the casino planet part) but the reviews/hype led me to expect something game-changing. However, the elements that the critics considered to be original were only original to the movies; they had been commonplace in the Expanded Universe for years so it was impossible for me to get as worked up about them.
And now I'm scared that the overwhelming hype in favour of Black Panther is going to affect my enjoyment of that movie...
It's all subjective, but there are some super discussed series that 100% live up to the hype.
Watchmen by Alan Moore. ('Nuff said.)
DD by Miller. (Redefined a cheesecake character into a fully formed tragic hero.)
Year One by Miller.
Sandman by Gaiman. (His definitive story with covers by the great Dave McKean defined my imaginative world in my early teens. The book challenged my young mind into reinterpreting old mythologies with Gaiman's progressive and dark sensitivities in a jarring yet defining way.)
Most of the Claremont X-Men run. (His run basically redefined comics from the 70's to the 90's. I started reading his books in the middle of his run and as a kid, his original books were legendary and his books available were the hottest things on the shelf.)
Usagi Yojimbo by Sakai. (Historical samurai stories told in a poignant, yet accessible manner? Yes please.)
Everything Lemire. (All his books I've read are breathtaking in the way it hits me in the feels by the end of the book.)
Hellboy & BPRD by Mignola. (I love the fact that I originally knew him from the Muir Saga and later, classic X-Men covers, but became a comic powerhouse in his own right.)
For some reason I was only thinking about Marvel books that live up to the hype. Usagi lives up in every way. Its my favorite series. I've read most of it twice and I plan on starting a third reread sometime this year.
DC: The New Frontier was so good that i started it around noon one day and didn't stop until I finished it.
The Boys - recently finished it, took my more than 2 years to collect definitive editions. It was hell of a ride and last few issues completely killed me. Didn't see it coming but it makes so much sense. Just dialogue in series is pure gold, you can have real connection with characters, you know where they are coming from, why they do what they do. Was heart broken at the end which doesn't happen often; hard to say which is better now, always though nothing can beats his Punisher Max run but after reading Boys I'm not so sure. My long term plan is to read everything by Ennis, next big run is Hitman and Preacher.
B.P.R.D. - recently finished my read-a-thon too, great stuff, Abe Sapien book was great for me but was disappointed by HoE.