Current I have ANT806, Mounted outdoor vertically on the North-East corner of the house to pick up major channels (RF-7, RF-10, RF-12, RF-13...), but signals are not stable.

Here is my TV Fool result
hxxp://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d23c50684a0d517

I am thinking about MS-2000.
Based on this, which antenna would you recommend?

Thanks a lot for any help!

Well according to TVfool CH 10 is in a completely different direction. And I'm not sure why you'd mount it vertically when Tv signals are horizontal in nature.

With signals that strong, an amp often makes reception worse. Get a real, conventional metal antenna, not a gimmick made of plastic. And no amp.

This small winegard should work well in your situation:
http://www.solidsignal.com/prod_display.asp?prod=HD7694P
Aim it ~175° (almost due south)
The only iffy channel may be RF10, but it will likely pick it up off the back side.

Aim it like this:
http://i25.tinypic.com/3481svp.jpg

If you still have trouble with the VHF channels, add an FM trap to reduce FM radio interference to channels 7-13.
http://www.mcmelectronics.com/product/33-341&CAWELAID=220403171

I only have this mounted on the side-wall, on the east and north corner of my house. I can not have this in front of my house (West) as restriction.

I did try to put this on the roof, EW and NS pointing, only pick up some channels. ANT806 is very directional. I can not have it picked up signals from both directions. Specially for RF-13, it has to be East-West pointing if it is horizontally.

With signals that strong, an amp often makes reception worse. Get a real, conventional metal antenna, not a gimmick made of plastic. And no amp.

This small winegard should work well in your situation:
hxxp://www.solidsignal.com/prod_display.asp?prod=HD7694P
Aim it ~175° (almost due south)
The only iffy channel may be RF10, but it will likely pick it up off the back side.

Aim it like this:
hxxp://i25.tinypic.com/3481svp.jpg

If you still have trouble with the VHF channels, add an FM trap to reduce FM radio interference to channels 7-13.
hxxp://www.mcmelectronics.com/product/33-341&CAWELAID=220403171

Is this VHF only? We have UHF channels as well.
I am having issue of picking up VHF.

The Winegard HD7694P receives both high-VHF (ch 7-13) and UHF.

Any comments on MS-2000?

The Winegard HD7694P has great gain for all the VHF & UHF channels being used in your area.

The MS-2000 typically receives TV signals "equally poorly in all directions." :) Typically, the best performing outdoor antennas are those that have no big pieces of plastic on them and are of tried & true conventional designs. Gimmicky or non-traditionally looking antennas are made & sold because people want and will often buy something that doesn't look like an antenna, not because of the way it works. In some cases they work fine, but in many cases, a coat hanger will also work fine, too.

Is this VHF only? We have UHF channels as well.
I am having issue of picking up VHF.

If I lived in your house I'd buy two antennas.

The first one would be the HD7694P that has already been mentioned. You could also substitute the HBU-22. Aim it at 168 degrees

For CBS I'd add a Y5-7-13 aimed at 274 plus a channel 10 Jointenna.

http://www.solidsignal.com/prod_display.asp?PROD=Y5-7-13

http://www.amazon.com/Channel-Master-Jointenna-0580-Combiner/dp/B001RQUP6K/ref=sr_1_3?ie=UTF8&s=electronics&qid=1251148688&sr=8-3

I only have this mounted on the side-wall, on the east and north corner of my house. I can not have this in front of my house (West) as restriction.If it's your house, HOAs cannot restrict antenna placement, if the restriction limits reception of the channels you want.