I use whatever is cheapest and has good reviews, this is true for guitar and bass. Right now my bass has a set of R Cocco 4 string electric's and while I am more knowledgeable with guitar strings they seem to be of fair quality and I have yet to really feel the need to replace them after months of playing.
Got my set for 15$ off ebay, they are advertised as "handmade strings" whatever that means.
"Richard Cocco Senior was born in Italy and came to the United States of America in 1951.
Richard entered the string manufacturing business at the time when the first electric bass guitars were introduced. Fascinated by this new instrument, he developed the Cocco method of hand winding to make new strings which proved to be so fine that some of his first customers wew America's legendary electric bass guitar inventors.
After 10 years of collaboration, Mr. Cocco recognized in Mr. Alfonso Annecchiarico the onlu one capable to continue his legacy. Today Alfonso Annecchiarico is the sole owner of R. Cocco™ strings and the only depositary of Richard's secrets. The best materials and the same machines designed and developed by Richard Cocco Sr. continue to produce guitar string that are exceptional."
- from their website
I may try something else out next for comparison as these are the only strings I have swapped onto my 1 bass.
For guitar I have used a lot of random stuff, lots of various Ernie Ball strings my favorite of which are the Titanium Slinkys which sound great and last a while.
Got some D Addario flatwounds I put on a semi hollow which sounded great, I never adjusted the action for them though so they were rough to play

I finally swapped back to regular strings and regret it, eventually I am going to get more flats and actually set up the guitar for them. Halfwounds are cool too.