Mark 8-16 by Joel Marcus

This was probably my favorite of all of the commentaries because of his close attention to biblical allusions.

Binding the Strong Man by Ched Myers

You know, I think a Marxist reading of Mark works rather well.

Mark 9-16 by Robert H. Gundry

What I liked about this was how curmudgeonly it was: very rarely do commenters engage other scholars to disagree with them the way that Gundry does. I also appreciated his close attention to grammar and syntax.

Sowing the Gospel by Mary Ann Tolbert

Tolbert was on my thesis cmte., so I have fond feelings for her approach to Mark. This is a solid commentary.

Eye of the Needle by Ken Follett

I enjoyed this. Very suspenseful.

Women in Mark's Gospel by Susan Miller

This is very good.

Mark by C. S. Mann

I can't recommend this. I read it mostly to be contrarian, but he doesn't assume Markan priority and it is just completely unpersuasive.

Reopening the Word: Reading Mark as Theology in the Context of Early Judaism by Marie Noonan Sabin

In general, this was disappointing, although the treatment of the ending of Mark was very good.

The Gospel of Mark by R. T. France

This is an excellent commentary.

Mark 8:27-16:20 by Craig A. Evans

This is a very good commentary. 

Hearing Mark: A Listener's Guide by Elizabeth Struthers Malbon

This is a great commentary if you want something really, really gentle. It's short and easy.

A Reordering of Power: A Socio-Political Reading of Mark's Gospel by Herman C. Waetjen

I have a soft spot for this book because he was one of my professors. It's a good title, with an important social justice angle.

The Gospel according to Mark by William L. Lane

This is pretty dated.

The Gospel according to Mark by Camille Focant

This was really good; there are all sorts of unusual literary insights here.

Reading Mark by Sharyn Dowd

If you've never read a commentary on Mark before, this is a good choice. It's reader-friendly and concise but meaty.

Ancient Christian Commentary on Scripture: Mark edited by Thomas C. Oden

I didn't love this. I always wondered if they were cherry-picking. Plus, I'm not sure how useful ancient commentary is when their interpretive assumptions were so very different from ours.

Mark: A Commentary by Adela Yarbro Collins

This is a good commentary because it is one of the few to really engage the Hellenistic literature; unfortunately, it has the worst layout ever.

Women and Jesus in Mark: A Japanese Feminist Perspective by Hisako Kinukawa

This is solid, with an important perspective.

The Gospel according to St. Mark by C. E. B. Cranfield

This is extremely dated; I read it mostly just for historical interest.

Mark: Storyteller, Interpreter, Evangelist by Francis J. Moloney

Decent.

Mark (Baker Exegetical) by Robert H. Stein

This is another solid commentary. 

The Gospel of Mark: A Socio-Rhetorical Commentary by Ben Witherington III

This is a solid commentary and one of the better ones. However, it oddly is sometimes quite friendly for the non-specialist but at other times, a little technical. So it is hard to say who the ideal audience is.

The Gospel of Mark as a Model for Action by John Paul Heil

I would describe this as a middle-of-the-pack, user-friendly commentary on Mark.

A Translator's Handbook on the Gospel of Mark by Robert G. Bratcher and Eugene A. Nida

So this isn't something I would recommend to others in general--as it is not a general commentary on Mark--but it was useful to me on occasion because it covers issues relevant to translators and so it was helpful as I was working on the Rendition.

Perspectives on the Ending of Mark edited by David Alan Black

This was interesting. I can't fathom Mark 16:9-20 as original, but I think it's worth thinking about whether Mark 16:8 was the original lending or whether a now-missing original ending was lost or suppressed.