The first two are definitely a weed, though I don't know its name. I have done the same as you, let that plant grow into the large sprawling thing you have there in hopes that it was some sort of volunteer beauty, but no, it's not. It has flowers, but they are insignificant, and the plant, while not as unattractive as some, is just not anything you want in your flower bed. The good news is that it is not a particularly noxious weed. At least around here (Southern CA) it doesn't reproduce that wildly. Just pull it out. The third photo looks like some kind of wild geranium; that is, a true geranium, not a pelargonium. At least around here, those are quite nice to have.

Oh boy!! Well, at this point I'm concentrating mainly on getting the garlic mustard out and only pulling others when they're right in with the GM. Hopefully the 2nd isn't as prolific as the GM, or I'll be in another world of hurt next year! I'm still dealing with the remnants of Jerusalem artichoke as well! Yeesh! OH BTW - could #1 maybe be an Actaea? I'm really hoping not to have to pull it - I've got a bit of it in there and it's actually kind of pretty in a group - I'm gonna keep an eye on it, and see if it blooms and what they look like.

Thanks, Rhizo. I have no problem with a weedy lawn, as long as it's all green and there isn't anything prickly in there. I'm certain there is more clover etc. than grass! I just don't care for bare spots, which I'm working on now, going through the watering new seed routine. I had a landscaper look at it and he suggested starting over--killing the lawn and reseeding the whole thing or putting in sod. I don't care that much, plus my priorities on "this old house" are more on the interior, not to mention the expense and mess. The landscaping just needs to be presentable so I don't look like the trashiest house on the street. :) I've planted a few perennials this year, and have beautiful azaleas all around the house that just need a little tlc and shaping. It'll take a couple (few!) years, but I think it'll look great with a little planning and pruning.

By definition, a weed is a plant you do not want. Do you want to keep the plant?