Where to get cross-sectional data

[smoothopia]

Hi, I'm working on a project for college and I have to use cross-sectional data to explain a certain variable using multiple linear regression. So far I've tried to explain GINI index using economic indicators, HIV prevalence with demographic variables and a lot more variables. The problem is that i always get really low R^2 levels.

I'd appreciate it you could tell me where i could get data sets that are easier to use without problems than these ones.

P.S.: I've tried eurostat, worldbank database and WHO, and every attempt I've made has adjustment problems.

Thank you SO much in advance.