These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Accidental Innuendo: In one very old strip, Dagwood is explaining to Alexander about how to make a Dagwood Sandwich, explaining what each ingredient brings to the whole. He explains to Alexander that "The sausage makes it gay". Yes Dagwood, I believe it would..... but not these days!
Memetic Mutation: "Don't touch that dial!" originated as a Catch Phrase that CBS announcer Hanley Stafford used to open the Blondie radio show each week.
Protagonist Title Fallacy: While the strip is named "Blondie", Dagwood is more often than not the centric character in a strip.
Covered Up: "Hanging on the Telephone" is a cover of a song by The Nerves, who were an obscure band. It had already appeared on their first EP. They were friends with the song's writer, Jack Lee, who agreed that Blondie should cover it. He also gave his song "Will Anything Happen?" to them.
The fact that "The Tide Is High" (originally by The Paragons) and "Denis" (originally by Randy & The Rainbows) are covers was little known by their fans at the time they were released, so had this effect. Since that time, the original tracks have become better known, but those by Blondie receive far more airplay.
Germans Love David Hasselhoff: They are much more popular in the UK and Europe than they are in the US. When they started, American audiences didn't know what to make of them, feeling they were too pop for punk audiences and too punk for pop audiences, plus there was the fact that they had a female singer, which was not common at the time, and meant Blondie were basically known as 'that band with the hot singer' (especially in their CBGB days). In the UK and Europe, audiences seemed to appreciate punk, pop and other genres in equal measure. To this day, Blondie are considered the quintessential pop band in the UK, whereas they are known mainly for their hit singles ("Heart of Glass," "Rapture," etc.) and their connection to CBGB's in the US.
I Am Not Shazam: Blondie is the name of the band, not a nom de plume for Harry herself.
According to the documentary "One Way or Another", they took the name from what truckers shouted at Debbie after she bleached her hair blonde.
Magnum Opus: Often considered to be Parallel Lines, since it's both their most consistent work and their breakthrough commercially.
Narm: Debbie Harry's rap on "Rapture" is utterly ridiculous.
Seinfeld Is Unfunny: So many Alternative Rock (especially in the modern Post-Punk / New Wave Revival) bands have been influenced by their look, attitude and their whole "Poppy, Punk-influenced Rock band with a female singer" schtick that many younger listeners may hear their music and wonder what's so special about them.