If I could fix just ONE bug on Grab.com, I'd fix...
Well, the "missing" photos and always-visible profile counter would be nice. But that's already posted in the Feedback forum.
Email notification of blog comments? Not actually that big a deal, as I use an RSS Feed Reader (in particular, Sharp Reader) to keep track of blog updates, which includes comment count. They do come in handy when I want to be alerted of a new comment in someone else's blog whose feed I don't normally subscribe to. Or friends-only blogs, as those will not come with a (public) RSS feed.
But the answer to this question would probably have to be: Blog Stats
Everyone on Grab has something they're a little more obsessed with than anything else on the site. For many, it's grabbles (hey, I was once amongst those!). For others, it's the good conversation and camaraderie to be found on the boards, often a good, healthy debate. For yet others, it's the pursuit of some sort of popularity and recognition, whether in the form of karma, Grab "royalty", or the quest for (even usage of) a badge and powers that elevate their stature above others.
For me, it's blogs. They are the feature I hold most dear to me here on Grab. I'll expand on that sometime in the future, as I recall seeing an old BID that deals with your favorite feature on Grab-- guess what my answer will be :-D
Another thing I enjoy is number-crunching. Which is why the various statistics involved in blog stats are interesting to me.
They've been a little iffy and I'm not sure I altogether trust the numbers I've been seeing ever since my Gold membership (and the ability to view these stats again) was resurrected.
So, in short... I'd love to see this feature working properly :-D