にもほどがある

1. 1Expresses exasperation that a behavior or quality has gone too far.Ex. 1
2. 2Expresses playful amazement that a positive quality is extreme.

This emphatic expression often criticizes someone’s conduct, as in both examples. It can also convey playful admiration for a positive extreme; compared with すぎる, it more pointedly invokes the idea that even this quality has its limits.

• 極まる・極まりないN1「極まりない」is written-style, attaches to な-adjective stems or 「…なこと」, and means 'extremely...' with a mostly negative nuance. 「にもほどがある」is colloquial, attaches to nouns, adjectives, and verbs, stresses going beyond the limit, and can also hyperbolically express praise.
• の極みN1「の極み」attaches only to nouns, is written-style and solemn, and describes emotions or states reaching their peak, with either a positive or negative nuance. 「にもほどがある」attaches to a wider range of words, is colloquial, and focuses on blame for overstepping the line or on hyperbolic praise, so the two differ in register and are generally not interchangeable.
• まじきN1「まじき」is written-style and declares, from the standpoint of status or morality, that something 'absolutely should not exist,' used attributively as 「にあるまじき＋noun」or 「verb＋まじき＋noun」. 「にもほどがある」instead says a degree is excessive, is colloquial and usually ends the sentence, so the two are generally not interchangeable.
• すぎるN4「すぎる」is a neutral 'too...' that attaches to ます-stems, stems, or nouns, while 「にもほどがある」attaches to plain forms or nouns, is colloquial, and carries strong displeasure or astonishment. When criticizing excess you can swap in 「すぎる」, but its sense of blame is much weaker.
• といったらないN1「にもほどがある」stresses crossing a limit that ought to exist and usually carries blame, whereas 「といったらない」merely exclaims that the degree is too high for words and contains no blame, being neutral in register. Both work for strong displeasure or hyperbolic praise, but 「にもほどがある」puts more emphasis on something being 'excessive.'
• くせにN3「くせに」is an adversative pattern meaning 'even though... yet...' that criticizes words or behavior for not matching one's status or conditions, and it needs 「の」after a noun. 「にもほどがある」only says a degree is excessive, attaches directly to nouns, and can also hyperbolically express praise, so the two cannot be swapped.

極まる・極まりない, の極み, and といったらない emphasize an extreme degree without the same “even this has its limits” framing. まじき judges conduct as unfitting, すぎる marks excess more directly, and くせに highlights a contradiction rather than an excessive degree.