My yard has seen an amazing turnaround in just the last year. The past 2 years I was complaining about almost 100% crabgrass coverage. I took it very seriously, and now I can only find the occasional crabgrass plant. I powerseeded in the fall, and was meticulous in my usage of pre-emergent crabgrass preventer. The powerseeded grass came up thick and lush, effectively choking up most crabgrass.
But I digress...
The one weed I had last year that seems to have come back is the one in the following pictures...