Honestly, if you are looking to be fit I'd say the best way to do that is keep things simple. Eat healthy is the hardest thing for most people so if you can stay on top of this you are off to a great start.
Next, I'd say all you need is a multi vitamin, whey isolate, and some BCAAs on lifting days. I would avoid supplements that have creatine or a stimulant in it. I also like to bring a banana for some extra potassium.
Finally, try to limit your consumption of beer.
I can certainly get more detailed if you like, but in my experiences (PHs, creatine, stimulants) the best results for me were the basics....clearly everyone's anatomy is different.
