I've been asked this question many times, by Nikon and Canon users mostly (as they make up majority of the camera-toting population of the country). I've owned 4 digital cameras in my time, the latter 3 being Olympus units. And each time I was readying myself to upgrade, a friend or a relative would ask me why I stick to the brand. I'm writing this entry basically to answer said question in case it is posed by anyone else who has yet to ask me and have not heard my long-winded answer.
The short version: Basically coz I'm used to it. Basically. Yeah. That's about it.
1) I like the 4/3rds standard. Olympus cameras use the 4/3rds standard, which, if you're not familiar with, is the same standard your monitor display uses. Shallow reason, fine. But I like the standard. I figure that you lose less detail in most photograph croppings compared to other brands. Canon and Nikon both use the 2/3rds standard, which is fine for your usual 4x6 prints, but you lose detail at both ends of the shot if cropping for 5x7 or even 8x10. It could be said that the reverse then is true for Olympus and 4R prints, particularly with top and bottom detail in landscape shots (sides on portraits) but who cares? Plus the 4/3rds standard helps to make the camera smaller than its 2/3rds counterparts, particularly true for the E-410 and E-420. I'm sure there are other arguments against the 4/3rds standard, specially locally, but who cares? :) I don't.
2) I like the feel. Mind you this is model-dependent, but I've been lucky enough to like the cameras I've owned in the past (with exception perhaps to the first digital camera I've ever owned, which wasn't Olympus - I liked it at the time, but digital wasn't cheap then - but a 1.3 megapixel Aiptek pencam with limited onboard memory with no flash or preview screen). Every button is placed logically, each function easily reached (specifically I'm describing the C-8080 WZ, though the C-5000 Z wasn't bad either). This can be said of any camera if you've lived with it long enough, but I liked this on the 8080 from the get go.
3) Storage: Truth be told, it wasn't exactly easy to find affordable XD cards locally when I first got the C-5000 Z. However, I was lucky enough to have been given a 256Mb card, which was a lot back then. Plus they've been getting cheaper and readily more available as time passes. Another thing I like about the C-8080 and all the E series cameras is their ability to use two storage media: XD and CF. This can come in handy in a pinch if you have the right memory cards.
4) Made for Digital lenses: That's one thing the Olympus - Zuiko partnership has over the others. Their lenses are made specifically for digital photography, and not just adapted from film. There's an advantage here that I've read before but can't put my finger on and expound on (if you happen to read this post and know what I'm talking about please feel free to comment so that I might, in future intigrate it into this post). That being said, Olympus lenses are a bit pricey. :) But then again good glass is always expensive.
5) For DSLRs, if you know where to look, who to trust and when to buy, these cameras are relatively cheap. :) But you get bang for the buck. I promise.
Sure. As a brand it's not quite so easily serviced (a point a buyer should consider always) as it's not quite officially an entity here like Canon is, but it won't stop Olympus loyalists around the country from patronizing the brand.
If you're an Olympus user and you read this, please leave a comment! :D