A lot of people now favoring 15lb - 20lb braid.
These thinner lines cast better and work very well with modern lures.
If you intend to use soft plastics with 3g to 10g lead heads and lures below 25g then I would suggest 15lb.
However if you want to chuck out big dexter type metal lures then use 30lb.
If you want to go "ultra modern"
Look up YKG 8X braid :spiteful:
But it don't come cheap!!
Power pro & Whiplash very popular