Nutsedge? I have this too. A broader coarse blade, grows in clumps. I am trying Scott's 4-step program this year, but so far I have been unable to get rid of it. Pulling it is satisfying, but it seems to come back somewhere else.

Definitely nutsedge. I have that in my lawn and have been trying to stay on top of it each year - pulling it by hand as well as using Nutsedge spray (found at big box stores). It's very easy to pick by hand and I've seen it less and less each year - I'm hoping that it will eventually go away with yearly overseeding and picking it as soon as I see it.