I have a shimano rod and reel that came together. The rod is a medium action, , takes 6-14 pounds of line, and is built for up to 1/2oz lure weight. I don't know the stats of the reel but it came with the rod so I'm assuming it's built for the same weights and lines as the rod, it is spinning. It's not an expensive rod and reel but it seems to do alright. I am looking for some good line. Probably around 10 pound line, for a spinning reel and medium rod, it will be used for light tackle, no more then 1/2oz, and I wil be fishing mostly bass I'd say up to 5 pounds, the odd pike, odd panfish, no extremely heavy fish though. I want a line that works best with those requirements, casts smoothly and doesn't tangle much, I don't know if monofilament is good to buy for bass but if you guys think it's good to have stretch for bass then let me know. Anyway good luck with this one, thanks a lot if you can help me. What line should I buy?

Mono is a very good line for bass. I personally have not noticed any particular problems with stretch, although amounts of stretch vary. My first consideration is that the line must be spinning-friendly, that is, relatively limp and low memory. Three such lines that are suitable that I've used recently are Trilene XL, Original Stren and Gamma Copolymer.

Berkley Big Game is a good line.  I use a lot of it never had any trouble with the stretch.  I would load it with some 10 lb.  Or for a low diameter but high strength you might want to check into some braid, a lot of people will reccommend Power Pro for this.

Try some Silver Thread AN 40 copolymer in #8 test. It will be fine for the setup you are using.

Power Pro!