You have to spend at least $50 to get a high-quality kitchen sink basket strainer assembly with a durable finish and a reliable stopper
mechanism. The best strainers have either a spin-lock or a
twist-and-drop style stopper. The spin-lock stopper doesn't
have any parts that can wear, but screwing it in and out can be
annoying. The twist-and-drop style is much easier to use but
requires occasional O-ring replacement.
Avoid push-in style strainers that have a nonreplaceable
neoprene stopper or a plastic knob. The plastic parts break and
can lose their sealing ability if exposed to boiling water.