Daddario EJ40

I've used these D'Addadio Silk & Steel strings for over a decade and prefer them over the standard bronze strings you typically see on steel string guitars.

The reason being is that these offer a different experience altogether - they sound beautifully warm and mellow and they're a lot easier on the fingers (emphasis on this last part!). If you're put off sometimes by the harshness of the strings on a steel-string, say compared to a classical guitar, you'll definitely want to try these out. I also find them especially well-suited for fingerstyle guitar. The strings are white in appearance, which I find quite appealing personally.

As mentioned they're my standard set of strings and I can't think of any cons. Just keep in mind the experience is different from your typical bronze guitar strings - you will likely love it or hate it.