You have an android tablet like Nexus 7 or android phone like Galaxy S2, S3, You want to stream videos from your tablet or phone to your TV. What are your options? Apple has AirPlay. You can stream media from iOS devices to Apple TV using AirPlay.
Update: Read 6 android apps for AirPlay & DLNA
If you have any of the following devices (via), you can stream videos, audio, photos from your android device to HD TV.
Computer/Old TV: You can stream media to Computer/TV from Nexus 7 or android phones
Internet Connected Smart TVs: Samsung, LG, Sony BRAVIA, Philips, Panasonic Viera, Toshiba
Game Consoles: XBox 360, Sony PlayStation 3
Media Players: Apple TV, Sony Blu ray, LG Blu ray, WD TV Live, WD TV Live Hub, WD TV Live Plus, Popcorn Hour, DirecTV, Logitech Revue
Audio Players: Denon, Sonos, Onkyo, Linn, Philips Streamium, Yamaha, etc.
DLNA/UPnP: Other DLNA/UPnP compliant media players. Please check DLNA site if you have DLNA enabled devices in your home. You might have DLNA device if you recently bought internet connected TVs, blu ray players etc
Google Play Store has below android apps. You can use them to stream media to any of the devices above mentioned.
1.iMedShare Lite: Download & Install this free app from Google Play Store. You can stream personal media & online videos from sites like YouTube, Facebook, Dailymotion etc via WiFi
2.Twonky: Download & Install this free app from Google Play Store. You can access & play videos, photos, audio from Your Nexus 7 or any android phones like Galaxy S2, S3 etc. You can create music playlists. If you install TwonkyServer on your computer, you can wirelessly transfer files between your phone or tablet and network.
With Twonky Beam, you can beam video you are watching on your phone or tablet to TV. This is similar to mirroring.
3.DoubleTwist: This is the most popular app for AirPlay. But you need to buy paid AirSync to be able to stream photos, videos, music to Apple TV, Xbox 360, Playstation 3.
How are you streaming media to your TV from Nexus 7/Samsung Galaxy Tab/android phones?
Also, read how to download movies Google Play Store for offline viewing