expression
nothing to complain about; perfect; couldn't be better
Used to express that something is so good there is nothing negative to say; often said with satisfaction or admiration.
この景色は言うことなしだ。
This view is absolutely perfect.
彼の演奏は言うことなしだった。
His performance left nothing to be desired.
文句なし also means 'no complaints' but is more about having no objections or faults, while 言うことなし emphasizes that something is so good there is nothing more to say.
A set phrase from 言う (to say) + こと (thing) + なし (not exist), literally 'there is nothing to say', implying no criticism can be made.