For trout, I fish mostly dries and rarely have a need to cast more than 30-35'; I have an Airflow for my 6wt, a Scientific Anglers Mastery 5wt that I use to overline my 9' 4wt rod for windy conditions, and a Cortland 444 4wt that I use with my 7' brush rod. I don't think I paid more than $30 for any of them and they've all worked great. For saltwater I've used whatever Orvis, Teeny and Rio, SA that was on sale and again, been happy with how they work for me. The only line I've ever had issues with was a Cortland Laser that was an absolute piece of junk. If you're a tournament-grade caster who can appreciate the nuances of the various lines (guys like Lefty Kreh can take a $5 level line from Walmart and make casts with his bare hands that are amazing) you'll have a different set of priorities than a hack like me who has 2 main requirements - 1. it doesn't cost an arm and a leg 2. it floats more often than not (and yes I do clean my line before I get on the water).

Regards,
Scott