I'm decent with numbers but words are my strong suit, so I naturally gravitate toward the word games. But the thing is, because I use words way more than I use numbers, I can 'feel' my brain 'stretching' more when I play word games. I'm guessing that feeling of stimulation is because I'm using my brain in a way I don't usually use it, whereas I use words all the time (talking, e-mail, reading, which is how I spend most of my leisure time).
OK, fine, maybe I'll start playing Soduku!