Windows XP allows me to do what I want (I'm not the power gamer I used to be). Pretty much every PC program runs on it.
Don't have a huge budget so don't buy Apple computers. I would use Linux if there were a similar level of apps to PC. Even iOS might not have a broad enough range of apps to satisfy my needs.
I did not find the Mac easy to use the last time I tried, even something as simple as opening a new tab in the background with the mouse was a nuisance. Maybe I would like a modern Mac if I got used to it but XP/2000 was Microsoft's crowning achievement in the OS arena and I'll keep using it until I want an OS that can utilise more than 4GB of RAM. Which might not be too far off.
I have a laptop that came with Windows 7. I installed Ubuntu but the Wi-Fi driver was vastly inferior to the windows one, only booted it up a handful of times.