I'm pretty sure Wagner and Liszt did away with cadenzas in any conventional sense towards the end of their careers. There is no grand, majestic coda to the Liebestode. You have a crescendo towards the end of the piece that only seems to burn out later on.
As for an actual "cadenza" in a traditional sense, listen to Lyn Harrell's ones in his performance of the Haydn cello concertos on EMI. One of the cadenzas in the first concerto actually has a blatant reference to Schubert's "Great" symphony (No. 9), which is quite funny in the context of Haydn, especially since Schubert wasn't even born when Haydn composed it. Like some of Harrell's performances it not 100% "authentic" (whatever that means), but highly engaging & amusing, which (as others above have pointed out) is one of the hallmarks of F. J. Haydn...
Besides the Rachmaninov rhapsody mentioned above, Beethoven does this all the time. The piano sonatas almost often seem to end in either a improvisatory fashion or a shocking 'surprise'.. like the ending of the Op. 31 No. 1 or the Op. 74
The most obviously 'ironic' ending I would say is the end of Mozart's 'Musical Joke' (intended obviously as a joke..therefore its ridiculous ending is predictable in a way) in which a colossal false ending shatters the illusion of quasi-music..(or really is this passage prophetic, anticipating Schoenberg 130 years early )
Sibelius' 5th has been mentioned, which is a classic case of an ironic ending, certainly ambiguous and unwonted, but the best example of an ironic ending in music to my mind is in the final piece of Schumann's Kreisleriana. The piece builds up to a maelstrom of passion, but dies away in almost nothingness, a throwaway ending. Hutcheson describes it thus: "the mystic last number vanishes like a wraith, leaving us at an interrogation mark'.
The finale of Beethoven's final quartet also seems to be an exercise in irony and obfuscation, with its insistent 'Es muss sein' 'Muss es sein' seeming whimsical yet vehement.
If you want to study a fun beginning, look at the score of the Enigma Variations by Elgar, Opus 36. The "original" theme is based on Pi. Yes, Pi, the ratio of a circles circumference divided by its diameter. The common approximation of Pi as a decimal is 3.142 and as a fraction it is 22/7. Elgar has both in his first four bars which are the crux of the original theme. The first four notes are scale degree 3-1-4-2. Easy enough. Fractional Pi is a little harder to find. Count the first 11 notes up to the two "drops of the seventh,." which Elgar pointed out in 1929 when no one had solved his enigma for 30 years. 11 notes x 2/7 = 22/7. Elgar also said there was a "dark saying" involved. Consider "Four and twenty blackbirds (dark) baked in a pie (Pi). Enigma solved. He wrote this piece in the year following the infamous Indiana Pi Bill of 1897 which attempted to legislate the method for determining Pi. Quite ridiculous, but Elgar turned it into a lasting treasure of classical music.
The Enigma I will not explain - its 'dark saying' must be left unguessed, and I warn you that the connection between the Variations and the Theme is often of the slightest texture; further, through and over the whole set another and larger theme 'goes', but is not played.... So the principal Theme never appears, even as in some late dramas ... the chief character is never on the stage.
In 1929, when he was 72 years old,he wrote:
The alternation of the two quavers and two crotchets in the first bar and their reversal in the second bar will be noticed; references to this grouping are almost continuous (either melodically or in the accompanying figures - in Variation XIII, beginning at bar 11 , for example). The drop of a seventh in the Theme (bars 3 and 4) should be observed. At bar 7 (G major) appears the rising and falling passage in thirds which is much used later, e.g. Variation III, bars 10.16. [106, 112] - E.E.
The endings of the first and last movements of Erik Satie's Embryons desséchés-- just when ou think its finally over... LOL
Speaking of Satie: the end of the brief opening chorale of Sports et divertissements-- this very stern set of chords becoming more dissonant leading to a final foreboding minor chord, slight pause... and a final major third added in the high register. Cute. LOL
At last to guess, instead of always knowing. To be able to say “ah” and “oh” and “hey” instead of “yea” and “amen. ” ~ Wings of Desire
Oh, SPR just reminded me of Schubert's Trout Quintet... huge false ending in the middle of the finale, so convincing it's hard not to start applauding right there. I got to see a performance at a chamber music festival with David Finckel playing the cello (immediately: heaven on earth), and before the piece began he announced to us the whole spiel about the false ending. When they got there a half hour later, some sorry souls began to clap. Hilarious!
That's hilarious, and I can confirm this! I played this piece with two other students last year and in our three performances we had that problem. I think we tried to start the second half immediately after the first half cadence to avoid the early applause..