I miss O'Leary's horribly, one of the two best comic shops I've ever been to.
Got my first true GA book there (Fawcett's Funny Animals #10), one of the only issues of All-Star I've ever had (All-Star #20, sadly sold on now), my first precode Super-Hero books (a handful of beat up Marvel Family books), my first issue of Scribbly (#9, $9); the first Platinum age book I've ever had (The Funnies #13). And that's just the Precode stuff that comes quickly to mind...
First pre-Adv 300 Legion appearance I ever got (Action #287). First Steranko art I ever saw (X-Men #50). First Neal Adams art I ever saw (GL/ GA #87). Got my GL/ GA #76 there, as well. I want to say I paid $14 for it at the time, the most expensive book I had ever bought up until then. One year for my birthday, my parents got me the GL/GA #85 they had in the case up front; signed by Neal Adams and Gil Kane both. (I got Denny O'Neil to add his signature to it a couple years ago, finally.)
Pogo Books. Sugar & Spike. Bantam Doc Savages. Dell Looney Tunes. An issue of Goofy Comics with Frazetta text illos. For Legion fans, That Damned Tabloid. Half a dozen Harlan Ellison 1st editions as a lot for 75c each, as I recall. Always something good there, even when my budget was next to nil. It was only a couple miles from my high school, so sometimes I went without lunch and went there instead.
I miss O'Leary's horribly. And I'm far, far from the only person in the area who does.