I always use compression and a small ammount of distortion..not anything recognizable as "distortion", but just to give it slight bite. (logic's distortion plugin is kind of nice for that..it can come off as subtle at low levels and you can control what frequencies that the "tone" are), but then again I am a crazy bastard mixer who compresses, limits, distorts, and bit crushes everything to varying degrees.
It could be your choice of mic for the vocals as well. That is almost alwawys the biggest problem. I do my vocals in my living room, with the mic right in the middle, through a mediocre preamp, but the mic sounds brilliant for the vocalist I usually work with, so it comes out crisp and clear without me having to do very much at all to make it cut through. Try a few different mics, and see if that helps. Changing position can help, but using a different mic can be like night and day. Every vocalist is totally different, so there is no right or wrong answer for a vocal mic. There are some people that even sing into a kick drum mic, or lavalere mic because it works for them. Just cause it's awesome expensive gear, doesn't always mean it's the best for the sound you want... at times cheap gear can sound better if it has the charactor you require for the particular performer.... Experimentation helps if you have access to a number of mics.