S&P 500 fund is one of the best long-term choices, especially for anyone under 40.   You're too young to bother putting much more than maybe 10% into a bond fund, if anything.
Besides the S&P and (maybe) a bond fund, you could put something like 30-50% into actively managed funds, no more than 2 or 3 funds.
Small-cap value funds have had a good run, but  even the fund managers are saying they're having a hard time finding bargains now.  The "gurus" are expecting large-cap to do well next.
Vanguard's international funds have had great returns, if you can get one of theirs like VEIEX it's a good balance to the S&P.  Other international funds would work too, but be careful, Janus for example had a badly-managed fund that underperformed even before they were caught in the market timing scandals.