Besides professional games, I think it is useful to comment on beginner games also. You can discuss this idea on Teaching go to newcomers / Discussion.
--Orcun
I have substituted the second game with a more competitive one which is more suitable for comments
--Orcun
I hope there will be other contributions. I don't have much opportunity to play with humans, which I think would be more suitable to comment.
--Orcun
Here are the sample games
WHITE BLACK INFO (handicap/komi/result)
BeginnerGameSample1: GNU Go v3.2 (10kyu NNGS) vs. Orcun (?2 days) (-/-/unfinished)
comments by: mAsterdam Charles Matthews , AndreEngels
BeginnerGameSample2: GNU Go v3.2 (10kyu NNGS) vs. Orcun (?4 days) (-/5.5/B+3.5)
comments by: AndreEngels
BeginnerGameSample3: GNU Go v3.2 (10kyu NNGS) vs. Orcun (?5 days) (-/5.5/B+17.5)
comments by: AndreEngels , Charles Matthews , Unkx80
BeginnerGameSample4: GNU Go v? vs. Timber (16kyu KGS) (-/-/unfinished)
comments by: AndreEngels , Bill
BeginnerGameSample5: Orcun (?2 weeks) vs. GNU Go v3.2 (10kyu NNGS) (3/5.5/W+62.5)
comments by: HolIgor , Unkx80, AndreEngels
BeginnerGameSample6?: (whiteplayer) (rank) vs. (blackplayer) (rank) (-/-/-)
comments by: commentor?
Timber:You can also find a lot of commented amateur games (and have your games commented) at the Go Teaching Ladder.