2004: Sony VAIO X505
Notable specs: 1.1GHz Pentium M processor, 20GB hard drive, 1.73-pound weight, 10.4-inch (1,024 x 768) display.
Sony didn't realize it at the time, but it was laying the groundwork for the next decade of laptops with the VAIO X505. The 10-inch system was so featherlight and slender that it was easy to take anywhere, much like a netbook or Ultrabook. If it weren't for the astronomical $2,999 price tag, it's possible it could have started a mobile-computing revolution.
2005: IBM ThinkPad T43
Notable specs: 1.6GHz to 2.13GHz Pentium M processors, 30GB or larger hard drive, 6-pound weight, DVD drive, 14.1-inch (1,024 x 768 or 1,400 x 1,050) display.
The ThinkPad T43 was the swan song for an era of computing when laptops were mostly for globe-trotting professionals. One of the last PCs to bear the IBM name before Lenovo closed its acquisition of IBM's PC business, it represented everything good about the ThinkPad badge: It was fast, well-built and relatively easy to carry in a briefcase.
2006: Dell XPS 700
Notable specs: Core 2 Duo or Core 2 Extreme processors, dual 320GB hard drives, dual DVD drives, dual GeForce 7900 GTX graphics.
Dell had built up a reputation for high-performance PCs well before 2006, but the XPS 700 was the system to own that year if you wanted a gaming desktop from a major brand. Its aggressive design still holds up today, and it was often as powerful as custom-built rigs. It was a dream machine at a time when you still needed a giant tower for serious online gaming.
2007: ASUS Eee PC 701
Notable specs: 800MHz or 900MHz Celeron M processors, 2GB to 8GB solid-state drives, 2-pound weight, 7-inch (800 x 480) display.
The Eee PC 701 marked the official start of the netbook craze, which lasted until the iPad's arrival in 2010. Its screen, speed and storage were very modest even when new, but it showed that you didn't need a big, expensive portable just to check your email at the coffee shop.
2008: Apple MacBook Air
Notable specs: 1.6GHz or 1.8GHz Core 2 Duo processors, 80GB hard drive or 64GB solid-state drive, 3-pound weight, 13.3-inch (1,280 x 800) display.
The archetypal Ultrabook. While it wasn't without its quirks, the MacBook Air successfully bridged the gap between ultraportables and full laptops. It was fast enough for most tasks, yet light enough that you'd hardly notice it in your bag.
2009: HP Firebird
Notable specs: 2.66GHz or 2.83GHz Core 2 Quad processors, dual 250GB or 320GB hard drives, DVD or Blu-ray drives, dual GeForce 9800S graphics.
While HP's Firebird line wasn't perfect by any stretch, it showed how efficient desktops had become. You could get a reasonably quick, ready-made gaming PC that both looked good and didn't swallow up too much surface area. It's arguably the prototype for the small-yet-strong Steam Machines that would follow five years later.
2010: Lenovo IdeaCentre A300
Notable specs: 2.2GHz Core 2 Duo processor, 500GB hard drive, 21.5-inch (1,920 x 1,080) display.
Although the iMac is virtually synonymous with all-in-one computers, Lenovo's sleekly designed IdeaCentre A300 was proof that Apple didn't have a complete lock on the category. Rather than glom the computer on to the A300's back, Lenovo tucked it away in the base. The result was a relatively subtle, stylish desktop that looked right at home in just about any environment.
2011: Samsung Chromebook Series 5
Notable specs: 1.66GHz Atom processor, 16GB solid-state drive, 3.3-pound weight, 12.1-inch (1,280 x 800) display.
Unlike the other PCs here, the Chromebook Series 5's real revolution was its software -- with Chrome OS, both Google and Samsung were betting that you only needed a web browser for most of your day-to-day computing. That was optimistic on a slow, Atom-based machine circa 2011, but the Series 5 helped launch a wave of stripped-down, affordable laptops that could do a lot without relying on conventional apps.
2012: Apple MacBook Pro with Retina display
Notable specs: 2.3GHz or 2.6GHz Core i7 processors, 256GB to 768GB solid-state drives, 4.5-pound weight, 15.4-inch (2,880 x 1,800) display.
Apple's 2012 MacBook Pro redesign was just an iterative upgrade in some ways, but it was also a bellwether for where laptop design would go. It wasn't just that extra-sharp Retina display that turned heads; this was also one of the first high-end, full-size laptops to ditch optical discs and hard drives in the name of both an easier-to-carry body and faster, flash-based storage.
2013: Acer Aspire R7
Notable specs: 1.8GHz Core i5 processor, 500GB hybrid hard drive, 15.6-inch (1,920 x 1,080) adjustable display.
Windows 8's touch-friendly interface prompted a flood of PCs that tried to be everything to everyone, and that's epitomized in Acer's one-of-a-kind Aspire R7. Depending on how you adjusted its multi-hinged display, the R7 could serve as a desktop, laptop or tablet. It wasn't especially good at any of these, but it revealed how eager PC makers were to keep you from buying mobile tablets.
2014: Microsoft Surface Pro 3
Notable specs: Core i3, i5 or i7 processor, 64GB to 512GB solid-state drive, 12-inch (2,160 x 1,440) display.
If you want a system emblematic of the changes to PCs in the past 10 years, you only need to look at Microsoft's latest flagship device, the Surface Pro 3. So long as you get its (practically mandatory) keyboard cover, it blurs the lines between tablet and laptop -- it's as useful for watching movies on the couch as it is for serious media editing at your desk.
Jon Turi contributed to this post.