I consider myself a grammar geek because I like to take at least a little time to make my writing grammatically correct while not sounding stiff. I obviously have my good days and bad days, but either way, it's something I enjoy doing. I sometimes find myself re-reading email over a half dozen times before sending, moving a phrase here, selecting another word there, going between looking at the overall structure and scrutinizing individual clauses. After doing all that and sending the message, I notice that paragraph I forgot to delete which contains just a single unfinished sentence fragment.
Even for those not as enamored of English as I am, the Grammar Girl podcast is still a worthwhile weekly diversion. The episodes are well produced and offer practical advice. Along with Mignon Fogarty, the show features guest writers such as Bonnie Trenga and Sal Glynn. Mignon is good at letting the individual styles come through when she reads the scripts.
Some episodes center around a grammar debate. One of my favorites was right after Apple announced the 2008 iPods. During the presentation, Steve Jobs called the new iPod Touch "the funnest iPod ever", and the slide being shown echoed that phrase. It seemed that you could hear a pin drop, as if the audience were wondering if he really had just said "funnest". Later in the week, Grammar Girl declared that there was a grammar emergency, and they quickly released a show dedicated to the word "funnest". She stepped through the reasons that, while sounding odd, "funnest" could work its way into informal usage.
Every now and then an episode gives hints as to how one can remember grammar rules. As an example, she says that avery easy noun will help you remember that affect is a verb while effect is a noun. Another memory trick she offers is that since i.e. starts with i, you can think of it as meaning "in other words", and e.g. starts with an e, which means it's an "example".
The show is very well researched and references are available in the transcripts. Sometimes the show notes contain additional content, such as the many examples of how to use appositives.
There are several other shows under the Quick and Dirty Tips umbrella, but this one seems to be the most popular. There are many times when I've thought I understood a certain rule, but through the show learned how many times the reasons behind the rule or got a more thorough understanding of how the rule applies. I definitely don't miss any episodes.