Let's assume you're at 10-feet for simplicity's sake.
The graph tells you that you're generally in the 720p band (for a 46-inch TV), and only if you're going to watch at 8-feet or closer would 1080p quality be appreciably visible to you. Even at 50-inches and at 10-feet viewing distance you'd actually be OKAY with a 720p set. You need to buy a 60-inch set and watch it at 10-feet, only then will you really visually appreciate 1080p quality. The reason why we appreciate higher resolution monitors is because we sit so close to them and our viewing distance tends to be in a couple of feet.
I won't add a disclaimer here, and tell you that this varies from eye-to-eye and all that nonsense--it actually doesn't vary for the average human eye. The fact of the matter is that viewing distance and resolution go hand-in-hand, it's great to have 1080p, but 720p isn't the end of the world for regular video content viewing. However, I don't want to lose sight of the fact that you're going to play games, and that means that often enough you will have text on the screen and it will look sharper on a 1080p set. So I'll conclude that 1080p is what you should get.
A 50-inch full HD Plasma set for around 60k--I would take that in a flash. But if we stick to your budget then this model is the next best thing: the LG 47LD460: LG 47LD460 : Televisions : Features, specification, reviews, online price, deals in India - Compare India
It's an older model, but it is available, pick it up if you find it.