I'm somewhat beginning to appreciate using various OS'es. It keeps you informed about what's going on in the world of tech and it gives me a somewhat objective view on the different systems out there - at least more so than when I'd only use a single system.
This story is probably not very interesting for a lot of people but it's nice to have a topic where I can share my experience regarding different OS's.
I've used Windows almost my entire life - didn't really have a choice since I was too young to buy my own computer and it worked alright. However, I remember working with a 24" iMac in 2009 and I immediately fell in love.
It was in 2010, at age 14, that I got my first Mac, a 1999 PowerMac G4 running Mac OS 9.2.2. It wasn't really useable because of the older software but as soon as I upgraded the RAM and figured out how to install OS X (took me a year...) it replaced my main computer, a Windows 7 PC. It sure as hell wasn't faster than the Windows PC but I liked the operating system (OS X 10.4) much more than Windows 7. Then again, I didn't have any problems with Windows but Mac OS just worked for me.
After a year or so, just before my 15th birthday, I was able to buy a Mac by myself; a 2005 iMac G5 (iSight) which also ran OS X 10.4. Of course this was a huge improvement, and by maxing out the RAM and upgrading to OS X 10.5 I finally had an 'up to date' Mac that was a worthy replacement for my main computer.
That didn't last long, though; after a month or three I had saved up enough money to buy an even more up to date Mac, a 2008 iMac. This was most definitely an upgrade to my previous iMac; it had an Intel processor thus was very powerful and it could run the latest and greatest OS. It came with OS X 10.6 but I never gave myself the opportunity to use it; I installed OS X 10.7 right away. I remember it being a huge difference compared to 10.5 since it was much more refined and this time I really had the idea I had a 'new' Mac.
It was around this time I also got my first smartphone, a HTC Desire S. It ran Android and I was very content with it. It didn't take long before I had rooted it and got familiar to the world of custom ROMs to make optimal use out of it.
Half a year went by and then, in april 2012, I had saved enough money to buy a brand new Mac. However, since I was going to university the next year I had to bring my computer with me as well so I decided to go for a portable computer. I bought a MacBook Pro just before the 2012 refresh (which I knew were coming but I didn't like the idea of not being able to upgrade my computer as I've done that with every Mac I owned thus far).
It came with OS X 10.7 but I upgraded as soon as 10.8 was available.
A few months after the 10.8 release I decided I wanted a new phone. Despite being such a Mac fanatic, I didn't want an iPhone because my Desire S had a 3.7" display and I found even that to be a bit too small for me. I wanted something bigger, so I bought a Samsung Galaxy Note. It ran Android 2.3, like the Desire S, when it originally came out, but I was already used to using Android 4.1 on the HTC so it didn't take long before having rooted my phone and installing Android 4.1 yet again. As soon as 4.2 came out, that ROM was installed on my phone.
Up until now, I hadn't really thought about getting an iOS device. However, a month ago I purchased my very first one; an iPad. I have to say that I quite like iOS in terms of snappiness and UI but I don't think an iPhone will be my first choice since I really like Android as well and I like to experience multiple OS'es to know what's going on in the world of tech.
TL;DR
1995-2010
Windows PC's (Windows 95 - Windows XP - Windows Vista - Windows 7 - Ubuntu 10.10 - Ubuntu 11.04)
2010-2011
PowerMac G4 (Mac OS 9.2.2 - OS X 10.4)
2011-2012
iMac G5 (OS X 10.4 - OS X 10.5)
iMac (OS X 10.6 - OS X 10.7 - Windows 7)
HTC Desire S (Android 2.3 - Android 4.0 - Android 4.1)
MacBook Pro (OS X 10.7 - OS X 10.8 - Windows 7)
Samsung Galaxy Note (Android 2.3 - Android 4.0 - Android 4.1)
2012-2013
MacBook Pro (OS X 10.8 - Windows 7 - Windows 8)
Samsung Galaxy Note (Android 4.1 - Android 4.2)
iPad (iOS 6)
These devices are still in my posession and (actively) used.