Do check out the site whattomine, a simple search will lead you to website, there you can compare GPUs, ASICs to mine on specific algorithms and the coins supported on that algorithm, how they have been performing and what profits you can expect.

Dont think this to be a one shot winner thing, mining is almost a full time job if you want to be able to hit that block once a while and reap the jackpot profit. Decide on your electricity costs and maintenance costs, those go in the negatives while the return comes in the positive. A load of youtube videos are also there about mining, you can check those out too.