1. Latest and greates mobile GPU you can buy - Games are running butter smooth, a lot of them in HD.

2. PC streaming works amazingly well with minimal PC requirements- I installed Nvidia Experience on my media PC which has an Athlon X4 645 and a GTX 660 and its able to stream most games at max game details without any lag.

3. Full access to Android app store games - all Android games at your fingertips at Android prices and subject to Android game sales. Max Payne - $2.99. GTA Vice City - $4.99, The Conduit - $2.99, Genesis Sonic games (with enhancements) $1.99...  Nvidia Tegra optimized exclusive games are also available which are all HD and look almost as good as stuff on HD consoles. 

4. Full access to Android app store period - Android has top notch apps you actually want to use like chrome browser and plex video streaming. Not limited and locked down baby versions that other gaming portables come with

5. Amazing battery life for a portable - 6+ hours of gaming and 10+ hours of PC game streaming

6. Open source and not locked down - a wet dream for homebrew and hacker folks

7. Amazing build hardware, buttons, speakers and screen - better than any other portable on the market right now

8. Comfortable to hold - unlike every DS ever made and PSP, it won't give people with big hands cramps

9. Built in extras other gaming handhelds don't/can't offer like miracast wireless streaming to your TV, true multuitasking, file system, ability to pair up with bluetooth controllers for 2 player on screen or on TV action...etc

10. Its a hardcore gaming handheld - despite all the extra functionality, this device was designed with hardcore gamers in mind. The full Xbox 360 like controller and ability to play non mobile, "core" games are front and center on Nvidia Shield. You will not find any links to Angry birds in the Nvidia Tegra gaming zone...

Some quirks with the device that I hope to see Nvidia Shield 2.0 improve upon:

1. To improve non gaming experience (browsing, video watching...) it could benefit from a sliding hinge that allows for screen to be flipped and facing the user. Much like this - http://www.maximumpc.com/files/u107541/windows7mobiledevice.jpg

2. Screen could be a little bigger - the bezel is quite thick and they could have easily added an extra inch to the screen size which would help greatly when you're playing a fast FPS like FEAR or COD

3. Missing front camera - kind of a no brainer

Other than minor gripes above, I really have no complaints about the Nvidia Shield. I never realized how impressive Android app store is in terms of "hardcore" games, and how many of those games are already optimized to work with a true console controller. This console is worth the price even without PC streaming due to the amazing library of console-like games it can play. The addition of PC game streaming though is something special and makes this the best gaming handheld you can buy. 

I am not sure how this will sell, but what I do know is that if it flops and the price plumments I will be picking one up just for the homebrew and PC streaming.

Just don't have the budget anymore for another handheld. Still, it is such a nice little device.

Good to know but are there even true Nvidia shield games? I don't need a device to stream my PC games to a handheld, I rather play them on a bigger screen.

Suppose you had only $300 to spend on a handheld, and you didn't own any current gen ones.

Are you really saying you'd buy Shield over Vita and 3DS? That's what's implied by "best".

But I don't own a game PC,,

Just my personal opinions on your list. Also I think you forgot the big negative, $300 ;)

I don't think this was released to sell crazy numbers so I don't see the price plumetting. The neat thing here is that even if it doesn't sell great, its stock android so the games selection and apps will grow and device will remain viable for many years to come.

Much like Nvidia 3D vision with didn't plumet in price for 4 years now despite being a niche product, I don't see this plumetting either. It may be $199, when Nvidia Shield 2.0 comes out...

NVidia shield is great, I recently bought one, but it's nowhere near the best portable handheld. The 3DS takes that place

It has access to all Andorid games and Nvidia shield optimized Android games. Android has a controller API so a lot of games support it out of the box. 

In terms of PC streaming, it obviously isn't a replacement for PC gaming but its extremely convenient to be able to play anywhere in the house. I will be able to squeeze in extra 30 mins of gaming every night once I go to bed lol...

Android games, exactly what I need a 300$ handheld for. Sorry but without it's own exclusive games that take advantage of the hardware and that I can play anywhere (unlike PC streaming) I don't see any value. I simply don't need (another) handheld without games, no matter how good the hardware is.