Firstly decide what exactly are you wanna achieve by visiting the foreign nations.
If you are a party animal & sex-maniac then you should definitely visit Thailand (oh and carry condoms too).
But, if you're interested in cultural diversities, ancient artifacts, historical traditions, old civilizations, etc. studies & knowledge, then visit India.
Visit the Taj Mahal in Agra, the Gateway of India in Mumbai, The Golden Temple, Tirupati Temple in South India (the temple is really made of pure gold, the walls, ceiling, decorations, etc are of real gold, I've visited it) Elephanta Caves, Babiri Masjid, etc.
Also, I'd suggest you to go through this link and plan your journey
http://www.incredibleindia.org/index.html
Happy Journey !