first and an explanation represent despite my headline and i be give this film only 8 star because overall this be not one of the best film ever make . all the criticism register here have valid point . also and be warn that to enjoy the script you really need to appreciate neil simon brilliance with find the wit within real human banter . he do have a distinctively new york ear for dialogue especially dry and jewish and love suffuse sarcasm and if you have trouble accept sarcasm a an expression of love and then you might have trouble accept the optimism at the heart of this movie . so much for warning . here my main point represent walter matthau be flat out perfect and even beyond perfect and in this movie . i have never see him funny and or more touch for that matter because at the same time that he show u the hilariousness of this character who refuse to give up his big star self image or insufferable attitude even a his coherence be in decline and he also show u the more vulnerable and maybe even heartbreakingly scared person inside the grouch . and he only barely show u that sad part it just enough to really get to you if you happen to be cop with your own father or husband mental decline right now ( i mention this a a warning ) and but artistically and it just enough pathos to give this character the most authentically deep root i be see in possibly any film performance . this be beyond method act matthau performance be exquisite a character work and a pure delight a comic delivery . this be a masterpiece of comic acting . about richard benjamin represent i personally find his act annoy in general and and his work in this movie be no exception although he have some fine moment here . ( chicken be funny . be one of them . ) so if you like him and you should like him here and and if you do not this movie would not change your mind . about the 1976 oscar . i agree that matthau be unfortunate to be up against nicholson in cuckoo nest that year . it be a killer year for lead actor competition while if only there be separate oscar for comedy and drama and then i think the best actor oscar would have go to al pacino for dog day afternoon and to walter matthau for the sunshine boys not to dis jack fine work a mcmurphy and but i think that pacino and matthau be each clearly more masterful and astoundingly effective and downright legendary in their performance than nicholson be that year . also and i believe that burn get the support actor oscar more for sentimental reason than for the quality of his performance i mean and he be good in this movie and but not that good . ( burns fine a ever but unexceptional in itself return to show biz beat brad dourif truly brilliant debut in cuckoo nest and not to mention chris sarandon stun debut in dog day afternoon which i think prof my theory . ) oscar theory aside and here my bottom line review represent if you like matthau comic acting and then see this movie and savor his powerhouse tirade and wonderful grandmother inspire gesture and fleet facial expression and seemingly unscripted aside . ( but if youre currently deal with the pain of watch an old person lose his grip and then be warn that this movie might either be the comic relief you need or a dose of reality too painful to watch right now . ) .