Well, I'm an Aquarius sun Virgo rising, but I act much more like a Virgo than Aquarius so I have two answers.
I get along fairly well with Leos, they're very trustworthy and loyal friends. Definitely more caring than all the other fire signs, and even masculine signs in general. I get along with Aries better, but I am definitely willing to concede that Leos are more reliable friends.
If my opposite is Pisces, then I can say no. I find Pisceans, while extremely nice, are also disloyal, flaky, gullible, and untrustworthy. And also can be immature at times.. but that's just a generalization. One of my best friends was a Pisces and she was one of the most loyal people you'd meet.