Well, just on this site, you can look up The Wingless' "All the World in One Girl" and Jormungand's "Dark Star Scherzo" mixes... both are really good examples of piano and keyboards...
Another place to look for piano stuff, orchestral and Christian style would be to look up Mark Schultz and Michael W. Smith...
Michael W. Smith's "Freedom" cd is incredible! It's more orchestral, but it has good piano riffs in it, and it's really good music...
Mark Schultz' "Letters from War" is a really good song to listen to also...