I'd like to know what is the current trend when it comes to options in a list of items.
Or, buttons at the bottom of the list which enable/disable based on the items like this:
Why not both? Experienced users could use right click in order to get the options that they are looking for. And less experienced users might look for the option that fits them. In this way, you support both groups of people.
Talking about trends, I can give my insight about web applications only. Although I believe that it can be used in more cases than web. This example is taken from Dropbox.