When we refer to something as being obvious, the connotation is often negative. Here are some synonyms for obvious that sometimes or always connote an uncomplimentary attitude about the subject at hand.
1. Blatant: crassly or offensively noisy, obtrusive, or obvious (possibly from the Latin word blatire, meaning “to chatter”)
2. Brazen: contemptuously bold (from Middle English brasen, meaning “brassy,” from the harsh, loud sound brass makes when it is struck)
3. Conspicuous: reflecting a lack or violation of good taste; the meaning can also neutrally refer to what is obvious (from the Latin term conspicere, meaning “to get sight of”)
4. Egregious: see conspicuous and flagrant (from the Latin term egregius, meaning, literally, “out of the herd” and figuratively connoting something outside of social norms)
5. Flagrant: demonstrating contempt for societal standards (from the Latin term flagrare, meaning “to burn”)
6. Glaring: Obtrusively obvious, with the connotation of embarrassment for the perpetrator (from the Middle English term glaren, related to the Old English word for glass)
7. Gross: reprehensibly obvious, plus other negative (and a couple of neutral) meanings (ultimately from the Latin term grossus, meaning “coarse”)
8. Rank: marked by a shocking display of poor taste; the term also has senses mostly related to coarseness or offensiveness (from the Old English term ranc, meaning “strong”)
See this post for a list of synonyms for ostentatious or referring to bad taste.