Over my 20-plus years of string playing, I have had the opportunity to try quite a few different varieties of violin strings, and have found that some are better (much better) than others. Violinist.com offers an excellent breakdown on types of strings. As the article mentions, string preferences can vary by player and instrument, so it's really best to try out some different types on your own. From my experience, my personal favorites are...(drum roll)...Evah Pirazzi strings. Usually coming in at about $70.00 per set, they're a bit expensive, yes. But I've found them to have an unusually rich sound that really improves the tone of my instrument. The only downside is that the beautifully rich sound does not last forever, and they can begin to sound dull after a few months. For students or intermediate players, I find that Dominant strings have a nice warm sound, are durable, and are fairly reasonably priced.
While it can be fun to experiment with different varieties of strings, it's important to remember that quality, mindful practice is the surest way to a beautiful sound. Lovely-sounding strings are just the icing on the cake.