I use the Russell 3000 and the ACWI (All Country World Index) as benchmarks. I don't think sector indices like the S&P 500, Russell 1000, EAFE, etc. are good measuring sticks for a portfolio.
For example, if the portfolio you're measuring is keeping up with the Russell 2500 that tells you nothing about whether mid/small caps are a good place to be. OTOH if that portfolio is lagging a total market index then it's time to decide whether you are satisfied with that given your strategy or whether you want to make a change. Same question if it's leading: why? and is that OK?
Measuring with sector indices like the S&P 500 is a popular tool for hucksters, too. A very dicey emerging market fund with recent good luck might crow about beating the S&P, which is totally irrelevant.