I recently asked my company for a new computer to replace my ailing x201 Thinkpad. They sent me a slightly newer x220. The rest of the office prefers the W series for the bigger screen and memory. I do a lot of work on remote machines and bike to work frequently enough that portability is more important to me. Both the x machines are solid performers and are robust enough to run serious PhotoShop as long as you aren't also rendering video and have twenty tabs open in your browser. The x220 is running Win 8.1 and I don't mind it at all compared to Win 7. I do have an old tower running Ubuntu and it works well but I hardly ever use it. Our home computer is an old MacBook Pro that is nearing the end of life. We probably won't replace it with another Mac. Yoga or Carbon are contenders. My daughter just got a HP Stream 13 for Christmas. It was less than $250 and seems to work really well but the touchpad is difficult for me to understand. The Thinkpad button mouse is just so much faster.

I used to work for Dell back in the early 2000s. Whenever someone would ask me for advice on buying a computer I would point them to the Dell Factory Outlet website. The products there include refurbs as well as products that were simply returned unopened for whatever reason. Since they can't be sold as new they are discounted. Everything is retested to make sure it is ready for resale and it is sold with a new factory warranty. The only caveat is that the systems are sold as configured so you can't necessarily get exactly what you're looking for.
Dell does a great job with the website though. You can choose exactly which options you want and the site will narrow down the available choices as you go. It's also real-time inventory so your selection will only remain in the cart for 15-20 minutes at most, however, it's not unusual for there to be several similarly configured systems to choose from.
When I left Dell I called my inside sales rep and had him configure a system for me at my employee discount. I had already spec'd the same system at the DFO. The DFO price beat my employee discount hands-down. I highly recommend checking it out.
We switched from Dell laptops to Lenovo Thinkpads where I now work and, for Windows systems, I'd rather have the Dells. The Lenovos feel flimsy compared to the Dells and aren't as easy to configure IMO. I've personally never liked the "eraser mouse" button and, apart from joshuman, I've never heard of anyone who does. That being said, we're moving to becoming an Apple shop as much as possible. A couple of departments are holdouts as they have some Windows-only software that precludes this. We much prefer supporting the Apple products. Despite not being as intuitive as Apple would have everyone believe we've found users who switch from Windows to Mac OS X adjust very quickly and our support calls drop noticeably.