What Vagabond says about keeping line is true. Kept out of sunlight it will keep for years. I put the spools in those metallic packets that so many snacks come in these days. If the top is sealed with a clamp or rubber band, it is kept in the dark and dry and will last for ever.
My favourite line for spinning or deadbaiting in heavily weeded waters is one that is UV reflective. It glows like a bit of purple cart rope in the sunshine and you can see just where your line is in relation to the reeds etc. For normal ledgering or float fishing any good neutral coloured line is good, though if I am going to fish at long distances I prefer a low stretch line. For bottom bumping at sea, there is nothing better than braided line, though I always use a neutral coloured mono leader of 15 - 20 feet. For lure fishing in the sea, I use some line I was given many years ago. It is a yellow Stren line. I look after it and it has served me well but again I use a neutral coloured leader.