My go-to strings are:

D'Addario EJ45 Pro-Arte Classical Nylon Guitar Strings, Silver plated wound[br].028 -. 043 Normal Tension

I've also used:

Savarez S.A. 500CR New Cristal Corum Classical Guitar Strings, Silver plated wound

.028 -. 042 Normal Tension

I use these on a Cordoba C-9 to play basic fingerstyle guitar. Both strings are nice to play with good durability. However, the best string for you will depend on the quality of your guitar, what tension you play at, your skill level and what style of music you typically play (e.g. Folk, Classical, Flamenco, etc). I don't own a top shelf guitar, I'm not an accomplished player and I'm not dancing around the room banging on my guitar and pushing the strings to their limits. So more expensive, higher quality strings don't make sense for me. But they may for you.

The more detailed your question, the better the feedback will be in these groups.

Nicolai