There are different philosophies for landscape creation. A common one comes from builders: use cheap, fast growing plants and smother the foundation. Another comes from landscape designers: overplant and thin later (attempting to give the fullest look the soonest.) Since there are some nice plants, you may have gotten a hybrid of these philosophies! But it looks like plants overwhelm the house and the resultant look is one of neglect. From the street it does not look the least inviting insofar as going to the front door. One can't see if there's a path to get there and it looks like it's probably going to be creepy with wasps, spiders and dirty leaves at the stoop. Personally, unless you LOVE to trim, I can't see why having plants that grow MUCH larger than the space allotted is a good idea. IMO, you'd be better off with a complete re-do and plants whose ultimate size is a better fit for the space. Below each window should be a shrub that's easy to keep 2' - 3' tall. (The shape is not a ball. It's a dome.)

The pine tree at the left corner is going to become (already is) much too large to be kept in the shrub form (with foliage to the ground.) In that position I think it can only be a tree and it's past time to begin removing bottom limbs so that humans can walk below it and the view to the first floor of the house can be maintained. If you limb it up, you can grow nice things below it. If you don't, you can't work comfortably below it or grow nice things. (When you first remove limbs, the tree looks somewhat awkward because the limbs remaining are at an upward angle instead of how the lower limbs are right now. But as they age and lengthen, they hang lower and eventually the natural look returns. It's best to remove limbs as soon as you know they need it. Wait and it's more work later.)

With a large, open yard, it will look better if there's some large shade trees widely spaced along the street. (Hope there are some behind this camera position.)

Thanks so much for the comments. And the picture is extremely helpful! I'm drawn to symmetry, and one of my concerns was that cutting down the plants would highlight that shorter side of the house, but proper landscaping can easily take care of that problem. i'm planning on attacking those plants as soon as possible, and I'm going to try and keep a rhododendron, because I love them too. We don't have any trees lining the street, which sort of makes our yard look like it's part of the neighborhood and less like part of our home, so new trees are in the plans too.

Rhodies are shallow rooted, so if you have a spot for them, dig a new hole, dig up in a big shallow circle, drag onto a tarp, and drag to the new hole. Mulch well. If you do this in the early fall, they have a long time to grow new roots before winter, but without the heat stress of summer.

Be sure to leave plenty of room between the house wall and where you set the new plantings to prevent being in the same boat several years down the line. Note the generous depth of the beds Yardvaark has drawn. I don't agree with limbing the pine up to above the roof line, but that is an aesthetic consideration you will have to decide on. Yardvaark likes all trees limbed up.

Rhododendrons, even large ones, transplant fairly well. Probably not a DIY job, but if you have a good spot for them in the backyard, you could hire a landscaper with a skid steer to move them for you. I did this in my yard with good success.

ETA: cross-posting about moving rhodies with NHBabs!

Plant small trees or shrubs. You can also use stones.

A possible place for a large rhododendron would be between the two windows on the right side of the house- looks like that might be the garage? As long as there is enough space for the walk to go around it.