There must be a copypasta for this somewhere...
KMPlayer has a far superior seek function to any player I've used, but the colour looks somewhat washed out. Doesn't do t/l notes all that well, and occasionally has trouble loading softsubs. Doesn't preserve font information, and always displays subs in a selected font. Default is Arial. Takes jpg screencaps.
Media Player Classic has a somewhat shittier seek capability, but looks more vibrant. Doesn't take screencaps unless you switch your settings from overlay mixer to one of the supported formats. Takes jpg screencaps. I can't figure out how to turn off the subtitle track to take caps without text. It's probably trivial, but that's really the only thing that bothers me about it.
ZoomPlayer would be probably the best if I could figure out how to use it. It also defaults to png screencaps, and I can't figure out how to change that. It also doesn't let you view the pictures until you've closed the file that you're taking the picture from, which is irritating. I'm probably doing it wrong. Someone feel free to enlighten me, cause I'd rather use ZoomPlayer if this particular setback wasn't so irritating. Subtitle track can be toggled off easily.