When I first started reviewing, it was really rare for me to see something a second time before publication. Now it seems to be happening for about 1 in 3 manuscripts I review, and most of them are completely unnecessary. Now, I don't mind if I get something back after saying "publishable with major revisions" as long as the authors have actually done some of the revisions! The last three manuscripts I've gotten back for a re-review have been:
1) something I said needed minor revisions. Isn't this something the editor or assistant editor can make a call on?
2) something I rejected for publication. I don't reject things lightly--I had major issues with the science and many of them are still there. If there ever is a time for adding reviewer 3 or 4, this is it, rather than sending it back to me. I don't think that papers that are rejected should go back to the original reviewers. If the editor thinks there is something the reviewer missed, it is time for a new review.
3) something I said needed major revisions to be accepted, and sent along 2 pages of suggestions. Almost none of them were implemented, and most were completely ignored. In their response, the authors pretty much said "The reviewer is wrong." without any additional evidence or support for their position. Why bother sending this back to me?
I find this particular trend really annoying. It is almost like editors don't want to make a call on anything anymore (and I can say that never having done it myself :-).
I've also had the situation where I get a manuscript from a big name group, and it is terrible. I reject it with lots of comments, and it comes back polished up after implementing all of the reviewer comments. I really resent that Professor Big Name has too many people to properly oversee/mentor their trainees in how to write papers and is farming it out to reviewers. It makes me not want to do such a thorough job.