North Grand Ridge is an easy summit to activate with a short (3.4 mile RT, ~600' elevation gain). The summit might be considered part of the "Issaquah Alps" series of summits that include Tiger Mountain, West Tiger Mountain, South Tiger Mountain, Taylor Mountain, and Rattle Snake Mountain. This report provides details on how to legally access the activation zone (AZ) and summit.
Walker Mountain is a Southern Oregon summit that could be a drive-up for those with a fully capable 4x4. However, the roughest part is also the start of a decent hike and getting to that rough spot is easy with a vehicle with decent clearance. Note that there is another Walker Mountain in Oregon - this is the one near Grants Pass.
Fielder Mountain is an easy 'road' summit in Southern Oregon. With several large RF sites at the top, the road is passable in a passenger car all the way to the summit - however a gate may put you on foot for the last portion.
Here's one of the closest "near" drive-up summits there can be - a few steps away from the car into the woods brings you into the Activation Zone. This is a very much out of the way summit, along Highway 101 on the Oregon Coast, about 14 miles north of Bandon. Note that there are other Peak 740 in Oregon - make sure this one is your intended peak.
There are three Wildcat Mountains in Oregon, so be sure you want the North Coast version south of Highway 26. The road to the trailhead is short and easy in any passenger vehicle, there's a good spot to park, and summit is in the Tillamook Forest, although the shortest access crosses private timberland. The hike is about 1.5 miles one way, and 400 vertical feet gain. This description I consider the 'no bushwack' version.
A friend of mine wanted to try a new, never before activated summit to start off his SOTA career and bring me along as his guide. Doing some preliminary research, this looked very much like a summit that would be very difficult to impossible to reach. From Google Maps, it wasn't too far from the road to the summit, but checking Google Earth, I could see that it was really going to be a steep climb for the initial part of it and through what looks like dense forest. I wasn't expecting that we would be successful. Luckily, I was wrong.
This is a drive-up summit near Tillamook in the Coast Range. Don't confuse this Peak 2260 with the other that shares it's name but is W7O/NC-101. (They are only 8 miles apart.)
Take Mills Bridge Road south from Highway 6 about 3.2 miles. You'll stay on the main track as you ascend this steep rocky road. You should be able to drive in a passenger car as long as it can handle a steep, rough grade.
I like big buttes, and I can not lie... 
I don't have much to add that K7NIT didn't already cover in her excellent report.
WW7D and I were in the area for the WA State QSO party (Salmon Run). This was the 2nd summit we did on this extremely wet Sunday in late Sept.
The road up to West Twin Butte is really fun... if you are on a motorcycle! The last 1/2 mile of this road is heavily rutted out, and would be a challenge for a high-clearence 4x4. Most people will probably opt to park lower down and walk up the road.
Today's attempted activation of Wilderness Peak W7W/KG-132 was my second attempt at my first SOTA activation. My cousin and I have been hiking all summer on various trails between Lake Washington and Snoqualmie Pass. In the last few weeks I've decided that I'd give SOTA a try. We made it up to the top of Wilderness Peak today where I was stymied by steady rain and radio problems. I called it a bust and will try again in a few weeks.