Shorted Netflix years ago on it's first big jump up. Shorted it at $297, it all time high at that time was 305, then it crashed down to 65-70, covered and went long. Kept my long position until it hit 700, then sold it. A couple weeks later they announced a 7-1 split, then it went from 95 to where it is now.
I've been a trader for years, made my first big chunk of change on Cisco Systems in the early 90's.
I wouldn't go long on anything now except gold. My advice now is to short the Dow or Russell 2000. Good market shorts now are the TZA, SPXU or FAZ. This market is so overbought it's laughable that people are still buying. If you insist on going long, look at commodities with a good dividend, miners, fertilizer, potash, nitrogen stocks. FCX, CF, Mosaic, etc.