Lots of things probably, but if I knew WHICH ones I obviously wouldn't be doing them! In fact, I can't figure out any way anyone on LW could possibly answer differently, which probably means I misinterpreted the question somehow.
Maybe you mean "in what situations do you have a problem with akrasia?"
Akrasia is a big topic here because it seems to be a common problem. However, excessive impulsiveness can also be a problem.
It's possible to think of impulsiveness as a sort of akrasia-- it's habitually insufficient effort put into self-regulation. However, doing something without thought has a different feel than low-energy time-killing, and probably requires a somewhat different approach to deal with it.
And there are sorts of irrationality which aren't very much like either. There's lost goals, and there's insufficient research-- doing something because ...
At today's meetup in Tortuga, we were supposed to discuss something we're currently being irrational about. In retrospect I could probably have done better than the item I picked (for example, it now occurs to me that I'm probably currently being irrational about bedtimes and sleep-cycle stuff)...
But the key point is that while straining my brain to think of something I was currently being irrational about, but hadn't fixed yet, I noticed myself being irrational in small ways too.
For example, I was sitting on the floor in a way that was beginning to strain my left thigh, but wasn't standing up and finding a chair...
So I stood up and found a chair.
I think it might be a valuable exercise to spend an hour practicing rationalist mindfulness, constantly asking yourself, "What am I currently doing that is not rational?" as though you had to find something to fulfill your obligation to an LW meetup.