1. PPF, lockin period 15 years, minimum 500 and maximum 100000 can be invested. Investment, interest and maturity all are taxfree, moreover its safe from any liability (in case of insolvency).Google about PPF for more information.
2. ELSS, lockin 3 years, investment and maturity taxfree. For long run say 10 to 15 years, should be much more profitable than any other taxfree investments. (Have a target of profit in mind, bcoz expected profit can be obtained much earlier than expected).
3. FD of banks, lockin 5 years. Interest is taxable. Good time to invest now as the interest rates are expected to be lowered. This is for risk free investments, but tax on interest will bring ur actual return down.
these are some of the 80c investments which I like.