The gym I worked out in in high school had a really awesome machine row that I liked alot. Haven't seen one since one as good since. Machine rows are basically the only machine I use, and I use them because I just don't have enough juice left after squats or deadlifts or what have you to do real bent over rows.
That being said, I like the ones where you sit and pull either a weighted lever arm or a weight stack better then the "machine t-bar" where you lay prone and pull a weighted lever arm towards you.
Oh, and I occasionally use the hamcurl machine when there's one that doesn't suck, I've probably done them twice since Thankgiving or so.