There is more to it than just picking a film. What type of photography do you do? Which developer would you use? Scanning and/or wet printing, self-developing or outsourcing it.
My suggestion is to pick 2-3 films of the speed you most likely will be using and shoot/process and see which one corresponds to your view.
It is tempting to get the cheapest - but also be sure to get brands that will be around for a longer time. Nothing worse than getting a filmed "nailed" down - and suddenly it is no longer available!
With film it is best to cut down on variables, stay constant with things like developer and processing - there are enough other things that can go wrong anyway.
My own system is easy, TriX for 400 speed, Fuji Across for 100 speed. I rarely push film so higher than 400 is rare for me (OK, I am also a great advocate for Kodak's XX Movie stock - but that is a different story - for something that matters - it is usually TriX).
If you want one of the best "all-rounder" films - look at Kodak's Tmax2-400. A medium speed film that rivals the grain of many 100 iso films today. A bit more finicky to shoot as it has less latitude than TriX/NP400/HP5+ - but again, a brick of 10 rolls (or even better 2-3 bricks of it) will get you familiar with it and you will know the ins and outs of it (and all films have its own idea how it renders the world).
Once you got the film nailed down - buy LOTS of it and just keep shooting. No better teaching aid than your own negatives!
