Which Lenovo Ideapad should I get?

I'm getting a new laptop, mostly for college (computer science major), and I really like what I've seen/heard from ideapads. There's several different series but I want to know which would be the best for me for the price. I'm pretty sure the Y series is the best and most expensive but I don't need that much power. But on the other hand the S series is cheap but too small for me, I'm looking for around 14 or 15 in. Any help is appreciated.