Most osts are really good, what people don't understand about osts of games/animes and opening/endings of anime or either music from foreigner languages is that usually they pack a lot of instruments and more complext series or chords, rifffs and progressions. Most common bands don't pack that many instruments, while in the musics I stated (osts and others) there's a nice combination of piano, guitars, violin, saxo, chellos, bass, drums, and other wind instruments that makes it sound so nice imo.
That being said I forgot to add these songs yesterday:
Rise Against - Help is on the way (kinda learn of this band and most others I put due to rockband 3, love that gay just for that reason, many awesome underated bands there)
Rise Against - Savior (Loved this song riffs and intensity)
Relient K - Be my escape (while i heard only 2 of this guys songs, I love this one with all of me, very nice mix of tempos and instruments)
Quietdrive - Deliverance (One of the most underated bands with one of my all time favorite songs, amazing way to put a synth into a song, nice way to put high range vocals and also the drums are doing some nice range of rhythms.
Dj Bobo - Everybody (I felt I can't end this post without my hands down favorite song of all time. I love that happy feeling it gives you, good vibes and everything are a must in this song. Just this time I'm posting the remix featuring inna, but I love both the remix and the original version)