Well, I don’t know how official any of these rankings really are.
I’m so unhip I can’t keep my pants on.
My first thought was “chick on the block”…
Thinking about it, maybe (something) in the hood? “'ho” is nicely alliterative but might be offensive!
hippest pelvis
As in, “I’m so hip I can’t see over my own pelvis!” courtesy of Zaphod Beeblebrox. But most of the people I interact with at work aren’t the literary sort, so it would probably go over as well as what you said.
…geriatric in the retirement home.
…tree in the forest
…flower in the field
…bee in the bonnet
…hippy in the Haight
Okay, I got nuthin.
I like what you said. I would have laughed and probably stolen it and used it myself.
I like hippest ho in the hood quite a bit … it’s so patently bizarre in my case that the offensiveness is negligible.
That’s where you went wrong - everyone knows it’s not hip to try hard at anything.
I wasn’t trying to be hip, I was sucking up to the Twicks. :smack:
Not the hippest poet in the salon…
Not the hippest sax in the band…
Not the hippest surrealist in the peanut butter…
Wow, that’s a tough one.
Surrealist is pretty good, though.
How about “not the hippest half-caf soy latte in the Starbucks”?
Not the hippest hipster in Hip-town
…which would clearly be demonstrated by uttering that phrase 
Your original response (“hepcat among the daddios”) is so perfect that I will attempt to remember it forever, in case the set up should come up in my life