A couple of reverb tricks to try.
-I will frequently EQ the send to the reverb differently from the dry signal. Vocals can muddy up from most natural sounding reverbs because, with a natural reverb (as in a real room or hall or plate), the high frequencies decay faster than the low frequencies. You can add a huge amount of reverb without muddying up the mix by using a high pass filter on the reverb send. This does not work as well when you EQ the return. You can also EQ different instruments going to the same reverb differently if you EQ the sends. On the SSL I used to work on, we would just bus the signal to two channels, and one would go to the reverb, the other would go to the mix. This would be more difficult with fewer channels, though.
-I, unlike many other engineers and producers, do not like to use a lot of different reverbs in a mix. I read about a producer who said he would rather have eight crappy reverbs than only one really nice one. I feel exactly the opposite. I want the reverb to sound as good as possible, and I prefer to use only one or two. I like to have the instruments sound as though they are in the same space together. I do not, however, want the different instruments to sound like they are in the exact same position in that space. If they each have exactly the same predelay, they are at the same depth from the listener. To avoid this, I will set up several sends to one reverb unit, and I will send all but one of the sends through short delays. This creates the effect of different predelays, giving each instrument a different depth. I will generally give the lead vocal the longest predelay (making it sound closest to the listener). One of my favorite things to do is to use a real plate (I really like the EMTs). I will send the background vocals directly to the plate, and I will send the lead vocals through a delay of about 30-50 ms. You get an absolutely beautiful sonic vision of all of the singers being in the same space, but with the background vocals a little behind the lead singer. This works particularly well when one person has done all of the vocals. It really adds a nice separation of the parts, while maintaining a cohesive sound.
-If you like a drier sound, don't use reverb. Use delay. Set the time of the delay to the tempo of the song, with only one or at most two repeats of the signal. It gives your sound a very nice space without washing it out. Here is a quick way to approximate the delay time. Get a stop watch. Start tapping your foot to the beat of the song. Turn on the stop watch at on the beat. Count 11 beats. Stop the watch on the eleventh beat. Move the decimal one place to the left. That is the length of a quarter note, in milliseconds. Half that time is an eighth note, double that time is a half note, etc. This will not be perfect, but it will be close, and it is then an easy job to move the time up and down until it is perfect. Of course if your delay has a tap tempo, then you do not need to do this, but my PCM-41s and -42s did not have tap tempo.
So there you go. Reverb according to Light. The only other suggestion I have about reverb is to try EVERYTHING. You never know what might work for a particular piece. On most pop music productions, I will use two reverbs. One for the instruments and one for the vocals. I lean heavily towards plate reverbs, myself, that's just me. Hell, one of my favorite production teams is Mitchell Froom and Tchad Blake, and they claim to have used reverb on only one record in the last ten years (I don't buy it, but whatever). They certainly do not use much reverb.
Try EVERYTHING.
Sorry if I ramble on, but it runs in the family.
Light
"Cowards can never be moral."
M.K. Gandhi
Use both, silly. 
