Creux du Van
My trip to Creux du Van featured quite a few road bumps such as a canceled train, a late train, more canceled trains...but it still remained a nice area to visit for the day. The train station at Noiraigue, a place to start the hike, is about 1.5 hours from Bern or Laussane, but about 2.5 hours from Zurich. This made it a pretty long trip with the train cancellations, and in fact I spent for more time on the train than hiking when I went.
The hike I completed was the Sentier du Creux du Van which is a circular hike from the train station. It is possible to drive up, there's no cable car, and there's a parking lot that sits back from the top a few hundred meters. To drive up follow directions for "Le Soliat". Unless it has changed there is no bus that goes to the top.
Hiking up I went along the "14 curve path" which is 14 switchbacks through the woods up to the top at 780m. After a miserable train experience I was eager to do the hike and go home, and so including the time I spent taking photos at the top I completed the hike in about 3 hrs. However, the stated time is about 4.5 hrs, and if you aren't decently fit the hike up will be a bit annoying in terms of time and energy to say the least.
This is compounded by the fact that the hike up is through the woods, and there is no real opportunity for a view until the very top, unlike most hikes in Switzerland, and so I actually heavily recommend driving for this destination. This will make it a much quicker day trip, and a more relaxing one. Of course, if you want to hike through the woods it is a doable hike, but I've seen enough of the Appalachian Trail that I don't find that kind of scenery all that interesting.
All that being said, if you are in the area I think it is an interesting place to go see as the views from the top are nice and the cliffs make for a dramatic picnic area.