Considering the current economic world trend (job uncertainty, economic crisis, unexpected events etc) what could be the best retirement plan for an individual who is in mid 30s?

Investment is the key. He/she must start to invest in a trust fund / mutual fund regularly, put a certain amount per month regardless of the market and economic status, by the time the retiree is about to retire, lets say in his mid 50's or early 60's, most probably his/her investment already doubled; by investing in a trust fund / mutual fund, this could possibly enables the person to atleast compete or surpass his/her country's current inflation rate. More so, if he/she is a risk taker and has a lot of knowledge about investments already, he/she can invest in the stock market.

You are thinking different and its good !!!

Give a read to the following article and you will find the answer.

http://www.forbes.com/sites/thebogleheadsview/2011/03/29/how-to-retire-early-plan/#5ea2491628c0