Celestial races are pretty cool. Sure, there are also angels (cool, yet not originally from D&D) but they are not the only celestial creatures. Since there are fiends of LE, NE and CE alignments, it makes sense that there are celestials of LG, NG and CG alignments. That way there's cosmic balance when all the extraplanar creatures fight themselves and are apparently too busy and/or tied to mount a large scale invasion to Material plane.

Owlbears are fun too.