Here's the valve I like, and I think is best non-ball valve available for less than $20 a pop:
http://www.nibco.com/assets/TS211BI.pdf
A) It's rated for steam service, so it has a teflon washer, not a rubber one. Rubber washers will eventually start to rot in water, and once that happens it's only a matter of time before the valve starts to leak and you have to replace the washer. Teflon is unaffected by water so teflon washers easily last 10 times as long as rubber washers. Also, Nibco had the presence of mind to make the teflon washer a standard washer size. The washer is 3/4 inch OD, which exactly matches a "1/2R" rubber washer, so if Nibco ever goes bankrupt and the teflon washers become unavailable, I can always revert to 1/2R rubber washers.
B) It has a full graphite packing, not just a packing gland. (The drawing shows a packing gland, but the note at the bottom of the page under the dimensions chart says that valves 1/2 inch and smaller come with a packing, not a packing gland.) That means that the packing can be replaced with the valve still in service. Just close the valve to block the water pressure, remove the handle and packing nut, replace the packing in the packing nut, put the packing nut and handle back on, open the valve and tighten the packing as necessary and you're back up and running again.
C) It comes with a stainless steel bibb screw holding the teflon washer in. I wish all small valves had that. Every valve in my building has a stainless steel screw holding the washer in.
D) The valve STEM is not made of brass, it's actually machined bronze. That means that there's no zinc in the stem, and that means that the stem won't corrode over the long haul like brass does. All of us have gone to replace brass bibb screws only to have them break apart under the force of the screw driver. That's called "dezincification". The same thing happens to the stems but to a lesser degree because companies that make valves have the good sense to use a brass for the stems that has a lower zinc content. The stems in these valves are bronze, and bronze is made from copper and TIN, not copper and zinc, so there's no zinc to corrode.
E) Finally, parts are available at a reasonable price. Not too long ago I purchased another dozen of these valves, and at the same time I ordered two spare teflon washers and one spare graphite packing for each one of these valves I have. I now have a bag of teflon washers and a bag of graphite packings. I don't have the invoice in front of me, but the Teflon washers cost about $2.00 each and the graphite packings were cheaper, about $1.50 each.
F) This valve is made with no washer between the bonnet and the valve body. They just machine both mating surfaces real smooth and tighten the bygeezus out of it when screwing them together. Tightening the #$%@# out of it stops any leaks, but it also makes it a SOB to remove the bonnet to replace the washer if and when necessary. That means I have to loosen the bonnet before soldering the valve in. In fact, I take the bonnet off completely, solder just the valve body in and then screw the bonnet back in, this time WITH a teflon gasket.
I go to any place that sells O-rings for pneumatics and hydraulics and ask for a teflon back-up ring for a "214" O-ring; it fits perfectly. O-rings come in standard sizes with the first number indicating the "cord diameter", or the diameter of rubber cord the O-ring is made from, and the last two numbers indicating the mean diameter of the O-ring. A 214 O ring has a 1 inch ID and a 1 1/4 inch OD, and so the teflon back-up rings will be about the same size, and I can get them in any town large enough to have a shop that stocks commonly used O-rings and back-up rings for them.
That way I can screw the bonnet back on without tightening the bygeezus out of it or having a leak. I could use a neoprene back-up ring too, but teflon back-up rings are flat (they don't have a contour to them to accomodate the round shape of an O-ring) so they work better as gaskets.
G) The only bad thing about this valve is that because the bonnet isn't meant to be removed, it has an 8 sided bonnet nut which requires an 8 sided socket to remove (cuz only the bonnet is sticking out of the drywall.) I got a 1 1/8 inch 8 point socket (meant for a square head bolt) and had it machined in a lathe to knock the points down a bit so that each point fits in the middle of one flat on the bonnet nut (kinda like Snap-on's "Flank Drive" sockets). Since the stem of the valve goes right through the 1/2 inch drive on the socket, I also had a 1 inch hex machined onto the end of the socket so that it can be turned with a 1 inch box end wrench. So, I essentially had to have a tool made to remove the bonnets of these valves to change the washers.