It's my 8mm TV Radian. I use it almost all the time. Most of my observing is with an SV152 apo, at 1,200mm focal length. So that's 150x. I'm pretty much a lunar and planetary observer. I use a 3-6mm Nagler zoom when the seeing allows, and most of the time it's at the 5 and 6mm settings.
However, lately I'm doing a lot of double-star observing, and that's using a Celestron MicroGuide eyepiece exclusively (sometimes with a 2X, 2.5X, or 4X PowerMate). This is a 12.5mm Orthoscopic eyepiece (which includes a special measuring reticle), and gives just about 100X in the SV152. It stays fairly sharp in the 4X PowerMate, too.
I begin every observing session with a mount alignment using an 18mm TV Radian, so that's probably my second most-often-used eyepiece.
I have recently been using one of 3RF's 31mm TV Naglers in this same scope and it's truly a spacewalk experience. the 24mm Panoptic is also very nice in this scope.
An Ethos might just give me a heart attack ... 