I have found the discussion on
Clearstation to be very instructive, especially on the major indexes (NASDAQ, Dow, and S&P).
Many of the posters have years of experience and some are full-time day traders. The thing I like about it is not only the level of expertise (because like on any site, half the recommendations are likely to be wrong), but because on any given day you will find both bullish and bearish arguments. There is a mixture of fundamental and technical approaches (although technical predomiantes). Some investors use momentum, some are bottom-fishers, some subscribe to Elliott Wave or candlestick analyses.
It is useful to see all these being discussed together and to get a broad cross-section of sentiment, because once the investing community agrees on the direction of the market, a reversal is very likely.
I sometimes use their "tag and bag" feature to find stocks and occasionally take a tip from a poster, although never without researching it myself.
There are a number of sites run by individuals who have good insight (eg, Decisionpoint), but this is the best community I know of.