Which home theater system is good ?

Yamaha RX-A730
http://www.crutchfield.com/p_022RXA730/Yamaha-RX-A730.html
And this speaker system are some of the best being made for affordable home theater:
http://www.crutchfield.com/p_735PCIN6B/Definitive-Technology-ProCinema-600-Black.html
Both should last you a very long time. I don't know what 20,000 INR translates into USD. However when it comes to quality sound, you have to spend money on it. Phillips is some cheap made sh**.

First, good sound for that large space can not be done for that budget (20,000 INR = US$365) Not even close.

Second, your "1000 watt" Phillips was not 1000 watts. No one is regulating this, decades ago here in the US the Federal Trade Commission cracked down on this but today it's being ignored. Consequently companies can just make up a huge arbitrary number and claim it as the wattage. Your Phillips was perhaps 100 watts or less.

Third, amplifier wattage is not how you determine output capability. Output capability is expressed in SPL (Sound Pressure Level) measured in dB. Amplifier wattage is a factor in determining this but alone the wattage is completely meaningless.

There are lots of complexities. A very small speaker in a very large room doesn't sound good even if it can play very loud. This makes for a very "hard" sound. To properly acoustically couple to a large air mass a speaker cone needs to be large. This is why you typically see very large speakers in large rooms sometimes even using large horn flares in front of the speakers. For the 1000 sq ft hall, you will never get good sound from any Phillips, LG or similar system. These inexpensive systems should be thought of as "toys".

For a room the size of yours the minimum ideal system would include a high quality receiver with preamp outputs. External amplification would be used for at least the left/right and center channel speakers. The main and center speakers would be large and there would be at least two large subwoofers having 12" or 15" woofers.

I don't know prices of availability in your country but here is a minimum cost system that would be just marginally adequate for a room of 1000 sq ft....

AVR US$700. http://www.audioadvisor.com/prodinfo.asp?number=NAT748
External 3-ch amp US$700 http://shop.emotiva.com/collections/amplifiers/products/xpa3
Main speakers US$700 http://shop.emotiva.com/collections/speakers/products/xrt62
Center speaker US$200 http://shop.emotiva.com/collections/speakers/products/xrc52
Surround speakers US$350 http://shop.emotiva.com/collections/speakers/products/xrm61
(2) Subwoofer(s) US$700/ea http://shop.emotiva.com/collections/speakers/products/xref12

Additionally you will need sources such as a BluRay player and any other source device you choose. You will also need an assortment of cables.

So for truly "nice" sound you need to increase your budget by a factor well over 10 times just to get something marginally adequate. If that's not possibly you are better off using headphones or setting up a smaller theater. You need a "real" system for a room that large, no inexpensive HTiB can provide good sound for any room much less one that big.

Of course "nice" sound is subjective and you may have a much different definition of what is "nice" or adequate. Even so, you still need to avoid all in one HTiB systems and buy separate components even if its in a much lower price level than the ones linked above.

mk