The Tablet PC was a growing gleam in the eye of Bill Gates when HP introduced a revolutionary tablet. The HP Compaq (HP bought Compaq in 2001) tc1000 crammed an entire Windows PC into a thin slate with a 10-inch screen sporting an active digitizer. It wasn't perfect, as the hardware of the time was anemic, and the tc1000 was very underpowered as a result.

The tc1000 was much thinner and lighter than anything else of that time, and was a full Windows Tablet PC. It was probably the greatest design and engineering achievement HP ever brought to market (even though design credit likely goes to Compaq).

The portable design of the HP tc1000 was only part of the reason it makes this “best tablet” list. HP realized that the keyboard couldn’t be dropped entirely from the Tablet PC, so it designed an outstanding mobile version for the tc1000.

The tablet could be easily snapped onto the keyboard for use as a laptop. The special hinge supported the heavy slate for comfortable use. The tc1000 could also be rotated 360 degrees for tablet use without detaching it from the keyboard. The remarkable hinge mechanism supported using the tc1000 and keyboard in every possible configuration, giving complete choice to the user.

While a remarkable product, the tc1000 was too underpowered to make it a great solution for most users. HP soon refreshed it to have a more powerful processor, and I quickly upgraded to the tc1100. HP made sure that all accessories purchased for the tc1000, keyboard and batteries included, were compatible with the tc1100.

This model was so advanced for its time that I used it for years in my work. It was fast enough compared to laptops of that time, and it provided the perfect solution for my note-taking and report writing.

Battery life of mobile devices was poor back then, so HP/Compaq went with an ingenious removable battery design. The battery was a relatively thin, flat shape that popped into a receptacle on the back of the tc1000/1100, leaving it flush with the slate. The ability to swap a spent battery with a fresh one made it possible to get all day mobile use of the tc1000/1100 at a time when most laptops could only get three or four hours using batteries much larger than that of the tc1000.

HP only sold the tc1000/1100 for a short while, but they were used by owners and businesses for years due to the lack of anything similar on the market. I used the tc1100 for years in my business, as it was solidly built and stood up to the rigors of mobile use.

The lack of Tablet PC sales drove OEMs to drop the pure slate form that was the HP tc1000's greatest feature, in favor of the convertible notebook form. This had the tablet permanently attached to the keyboard. The display would rotate and fold down over the keyboard, forming a bulky tablet PC.

We slate afficionados didn't like this change, but we adapted to the new reality. These new convertible notebooks were not as comfortable to use as tablets, but they were better laptops.

When Lenovo introduced the ThinkPad X61, I snagged one as my beloved tc1100 was getting long in the tooth. The X61 was unique in that it was a full ThinkPad laptop that could also be used as a real laptop.

The ThinkPad X61 was bulky and heavy compared to modern tablets, but it was thinner and lighter than many laptops of that era. It could be used for hours at a time as a tablet, and the 12-inch display made for a great digital notepad.

The battery of the X61 was user replaceable, so it was possible to get that important all day use by carrying a spare. It stuck out from the unit body which wasn't as ideal as the tc1000 solution, but it formed a handle for holding the unit in tablet mode.

What set the X61 apart from the competition of that time was the fact it was a real ThinkPad. Those were the standard for business computing and with good reason. The X61 was an outstanding laptop with the famous ThinkPad keyboard, and a good tablet.

The ThinkPad X61 got a lot of miles during my use, and thus makes this shortlist of great tablets.

HP continued to leverage its acquisition of the innovative Compaq by introducing the 2710p. This convertible notebook was a full business laptop, but was as thin as anything of that time. It raised the bar for convertible notebooks as the thin (<1inch) form was more fitting for tablet use than anything else on the market.

The HP 2710p had sleek looks and a simple design before that was widely viewed as a good thing. It was pleasant to hold in the hands for long periods of tablet use, while also a great business-quality laptop.

HP addressed the ongoing battery problem of the time by producing an innovative optional slice battery. This thin battery (0.5”) was precisely the size of the bottom of the 2710p laptop, and was simply snapped onto the bottom of the notebook. This more than doubled the battery life of the laptop, and since it was hot swappable it could be added/removed without shutting down the system.

The design and engineering of the 2710p was so good that HP produced several subsequent refreshed models for a few years. It deserves being on this short list of great tablets.

This won't make iPad/Apple haters happy, but the iPad Air is definitely one of the five greatest tablets ever made. You can make a case for including the original iPad, but in this writer's opinion the iPad Air is a far greater achievement for Apple.

That Apple could put such processing power and storage options in a slate so thin, so light, is an outstanding accomplishment. A sleek tablet of the size of the iPad Air, weighing only a pound, is amazing.

Say what you will about the OS driving the iPad Air, it is a solid mobile engine for the tablet. It has a huge ecosystem offering a big selection of really good apps, opening a world of productivity and play for owners.

With the recent introduction of Office for iPad by Microsoft, the iPad will assume a even larger role in the enterprise than it already has. This isn't Apple's doing, but it does add a higher value to the iPad Air.

The great hardware, simple design, and good apps make the iPad Air one of the greatest tablets ever made, and worthy of inclusion on this list.

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Many may disagree with designating the Kindle Fire HDX as one of the greatest tablets of all time, but Amazon has hit all the right buttons to make it so.

The hardware of the Kindle Fire HDX is not only a tremendous value, it is very good compared to anything that's come before. From the processor to the fabulous high-resolution display, Amazon has hit the ball out of the park.

Simple hardware design choices, like the power and volume controls on the back of the unit, work together to make using the Kindle Fire HDX feel natural. Amazon's engineers have carefully considered the hardware and software design to make the tablet intuitive, easy, and enjoyable to use.

The tablet is the perfect platform for using content of all types, and making that easy to do is ingrained in every aspect of the Kindle Fire HDX software. The unique home screen has frequently used apps and content to bubble up to be right there where the user wants it. This makes the Kindle Fire HDX the most enjoyable tablet to use the author has ever seen.

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