[Vervious]

It seems to depend on how specialized you are. I bet it would be very difficult for any automated tool to understand how good a paper is. Until then, you have to rely on other people who understand the paper, to get good paper recommendations. Most papers are incredibly specialized and I bet can only be totally understood by a few dozen/hundred/thousand people (depending on field?). In other words, if you are a student, ask your advisor/professor. If you are looking for general papers to read about systems, someone's probably written a blog post about it. Or popular science magazines (e.g. Quanta) might be nice.

Oh, or you can browse conference proceedings of the top conferences (in CS, at least.) (Though those are also, gigantic, and you probably want to filter even further...)

I feel that Google Scholar Alerts are only useful once you can filter paper titles / taglines by yourself, which requires tremendous expertise. I would be very surprised if any automated tool could replace other people and their technical expertise (which took years of training to develop) as a paper filtering tool. Otherwise you might as well automate peer review.