This is what I used to create the personalized invitations for my sister's bridal shower. I adapted the invitation template from this page. I wrapped it (and the envelope template) in a LaTeX macro, and wrote a short python script to iterate through the guestlist and call these macros for each person.
I prepared the guestlist using a table in emacs org-mode, which I exported as a csv file. Of course, a csv file could be created any other way as well. The sample guestlist here is based on the most common names in America, or at least the most common names circa 1990.
We got some nice cardstock, printed them, and they turned out great. This was also the first time I used LaTeX for something outside of school, which was very satisfying.
