Luke Duke. Not Bo, just Luke. I’m a little bit embarrassed to admit this now, but there it is.
Actually I’ve gone most of my 36 years without ever having a celebrity crush. In fact, the whole idea seemed kind of alien to me. I just didn’t get it. Then, I watched the first Horatio Hornblower movie… and now, I Get It. I dunno why, but something about Ioan Gruffudd just makes my heart beat a bit faster. I think he’s gorgeous.
Cricket
Jennifer Love Hewitt.
I had a thing for her way back when she was on Kids Incorporated. This was when I was an unincorporated kid of course. 
I thought she was the greatest thing that I had ever seen. Still do.
Never had one, actually.
I like the perfomances, but I was never into the whole Celebrity-Worship thing.
Shaun Cassidy. 
From the first time they were on the Sullivan show, I had such a thing for John Lennon. I’ve always been able to spot real talent.
The first time I saw the 1955 movie “Rebel Without a Cause” I was 12 years old. If Natalie Wood had kissed me the way she kissed James Dean I would have willingly died on the spot as One Happy Boy!
Annette Funicello from the Mousketeers.
Gad! Am I really that old???
IIRC, Lisa Dean Ryan from Doogie Howser
(Followed fairly soon by Jennie Garth in the early years of 90210… and more than twelve years later she’s still quite the babe. 
)
Emma Peel in a leather jumpsuit. Grrrrrrwwllll.
I was a bit deviant even as a toddler.
Chalk another one up for Shaun Cassidy. <sigh>
Mark Hamill. To this day, I would totally do Luke Skywalker. I spent a few years wishing I was Princess Leia, then RotJ came out and I changed my mind about wanting to be her.
Well, when I was a wee thing, I had a serious thing for Speed Racer. :o
If you’re talking about actual, you know, humans, it would probably be David Cassidy. The way he sang the word “you” like it was “ewe” made my heart flutter.
When I was ten I had a little thing for Ricky Schroeder. At 15, it was Johnny Depp in 21 Jump Street. (Alias obviously has excellent taste…)
As a very young girl it was Jackson-5 era Michael Jackson. Man, he had the moves, he could sing. Wow. Donnie Osmond wasn’t good enough to comb out Michael’s afro. After MJ it was Cat Stevens. Sexy, dreamy eyes.
StG
How in the hell can I be the first person to say Madonna?? We’re talking circa 1984 or so, the “Like a Virgin” era. Oh, how my 11 year old heart would flutter.
Also, Alyssa Milano when she was in “Who’s the boss?”. Seeing as how she dried up, so to speak, I had pretty good taste for an 11 year old.
It was a weird tie between Lisa Gerritson and Mary Tyler Moore.
It’s a toss up. When I was 8 years old I had super painful crushes on Elvis (this was after he died, mind you!) and a combination of Davy & Mickey from the Monkees. The show was in syndication on a local channel one summer.
So, in 1978, I was in love with 1 dead guy, plus 2 guys from a 60s television show.