Is it best to buy long term stock or short term stock?

Financially speaking, one makes the most money by buying the best 'short term' stock in one's retirement account. The problem of course, is that you have to keep finding the best 'short term stock very often which is impossible.

I think Buffett has solved this problem by buying the best company he can find (or part of the company with stock - say, 10% of IBM) and holding it forever.

During the height of the last Stock Market bubble, Buffett was asked on CNBC, something like, - Coca cola and your other stocks are now selling for 100+ PE, so when will you sell them ?

He said, something like, 'Our holding period is forever'. My understanding was ( and is): If you hold 10 good stocks forever you will do fine. It is not that every one of your 10 stocks will do fine, but ON THE WHOLE, you will do fine.