Anywhere is fine. I wouldn't want to pay commissions though. Etrade doesn't charge commissions for a number of vanguard mutual funds. Most of the large brokerages don't charge commissions for the ETF versions of vanguard mutual funds (like VTI which is the equivalent of VTSAX). Most of the large brokerages also offer other mutual funds (and ETFs) that are also good and on which they don't charge commissions. Long story short: there are plenty of good options available at Vanguard, Fidelity, Schwab, Etrade, and TD Ameritrade (among others, I'm sure), so just pick the one you want and people can probably tell you what some good investment options there would be.