Detective Comics #519 is the first Batman comic I ever recall reading. I think my dad bought it for me and just dropped it on me at some point, right about the summer before third grade. I remember this for a somewhat specific reason, which I'll get to in a minute. It was also the only Batman comic I would read between 3rd grade and 5th grade.

The issue's writing is handled by two of my favorites from pre-Crisis DC. Gerry Conway on plot. Paul Kupperberg on script. Pencils are by a "Don Newton". I don't know Don's work, but its really, really nice. Well rendered in an illustrative style. I don't think this cover is Newton. It might be Aparo, but I have no idea.
(update: The cover is Aparo. And, sadly, it seems Don Newton died suddenly in 1984. Here's a web-gallery of his work for you to enjoy.)
The story is the second half of a tale (which began in the previous issue) wherein Batman confronts a terrorist holding Washington DC hostage with exploding blimps. Its actually a pretty cool story, with Batman unravelling the villain's scheme.
The problem: Not only is our terrorist wearing a grape-colored chauffer's outfit, his nom-de-crime? Colonel Blimp.
Not exactly a name geared toward striking fear in the hearts of the populace. And a little on the nose, I think. I am unsure why Conway and or Kupperberg slacked so badly on the villain's name, but there you have it.
Blimp is also awesome enough to give his henchmen themed outfits.

I can't tell you how much I would pay for exactly that same shirt.
Part of the plot includes Blimp's henchmen trying to hi-jack nuclear subs in the arctic. Robin heads off to run interference, which seems short-sited with his perpensity of wearing green undies and precious little else south of the equator. Fortunately, the Bat-team seem to have ready-to-wear bat-onesies.

Robin looks adorable in his little outfit.
I was especially impressed by a "Batman escapes from the exploding blimp" sequence. Well rendered, well-framed, and with the appropriate sense of tension. Jack Bauer, eat your heart out.


click on these panels for full detail
Now, THAT is an explosion. Well done, Don Newton! It's almost like you didn't use Hindenburg photo reference.
Now, why was this my last Batman comic for a while?
Back in the 80's, DC had opened the door to writers using the words "damn" and "hell". At the Steans house, profanity was taken with all seriousness. We could see movies with "dirty words", but it wasn't until the Eddie Murphy incident of 1984 that blue language began to creep into our household's entertainment with any regularity.
Marvel always substituted words like "blazes" for "hell". And in the X-books, people couldn't make a cup of coffee without telling someone "it hurt like blazes" or to "go to blazes". And I think, honestly, it was part of why I started reading Marve before DC. That, and Marvel was never was all-out weird and apocalyptic as DC could get.
Anyway, all I could recall about this comic 20-odd years later was that it had a swear in it somewhere. Lo, those many years ago I'd been pretty scarred by stumbling across a swear in my funnybook.
In fact, when my third grade teacher put some comics on a shelf for us to enjoy during quiet reading time, I was horrified to see the image of Colonel Blimp and Batman on one of the comics and made a special point of telling Ms. Martin that those batman comics were for older kids because they had swears in them.
After scanning the comic, this is the only use of any four-letter word in the entire comic:

Wow. I was a sensitive kid. My parents didn't even have to find this smut themselves, I was so busy self-censoring.
It was TWO YEARS before I read Batman again. And I honestly have no idea what happened to that copy of this comic. Just as I have no idea where my Bugs Bunny comics, etc... went.
But I don't think Ms. Martin ever pulled those comics off the shelf, for which I salute her
I don't think we ever saw the likes of Colonel Blimp appear again in the Batbooks. Perhaps because it was just a little tough to take even our Dark Knight seriously when he's delivering lines like:

So a salute to sweet, sheltered little Ryan and a life before he used swears with all kinds of regularity. And a salute to this comic, which is still really good after all these years.