If you have dial-up, I assure you that that at least one of these songs is worth listening to.

These links will take you to the page with the song playing on Blue Laguna.
Stars of Tears
Restored Pieces
Pain
Kokoro

If for some reason those links don't work, here's the link to the pages you can get to for the songs.
http://bluelaguna.net/music/xs/mp3s.php
http://bluelaguna.net/music/xgost/mp3s.php

But anyway, I just find the instrumentals and her voice absolutely spectacular and above any other vocal track in any Xeno game.

To be honest, her voice kills me (and that's not meant in a good way). I'm glad she didn't return in Episode 2 & 3 again =x . But that's just me... to each his own, I guess. I'm sure there are others who like her performance as well, but I'm not one of them. xP

Yeah I liked her singing. I do have to confess that I liked Faye Wong's work on FFVIII more than her Xenogears songs. Now overall, Xenogears' soundtrack is my favourite, i rated high above anything and I think Mitsuda kicks Uematuse's ass in every aspect of the term. However, Joanna's singing is just bellow Wong's, still i did like Stars of Tears a lot.

I would agree with Xerno, in comparison to the FFVIII girl, she did a lot better than Hogg. But that is also just me, not trying to put things against you Razael or SA. Personally I prefer songs that are just instrumental. There are only a few from bluelaguna I have that could be called an actual song with lyrics. Probably one exception would be the Song of Nephilim but that's just one hymn and...well creepy.