Define "R.O.I." Are we talking just straight cash return? Or are we looking at "qualitative" things like getting a girlfriend and not living with your parents?
If you are just looking at straight cash return, you'll continue to live with your parents, save aggressively and invest the savings.
As you've probably found out, there is more to life than just maximizing your cash "R.O.I." No one here can tell you what is better to buy, as we don't know what value you put on certain things like roommates, an actual bedroom, what part of town you can tolerate etc. Given the fact that you are here asking complete strangers, I would recommend you rent to find out for yourself what you value. And one thing is almost certain, if you do get a girlfriend and eventually tie the knot, she probably will want something different than what you picked out.
As far as your portfolio, I'm a big believer in lazy portfolios. With your small balance, I'd go with one of the simpler ones. http://www.bogleheads.org/wiki/Lazy_Portfolios
PS. a home is not an investment. It is a place you live.