When should I stop watching filler episodes?

[tantei okuoku]

I am currently around 325, and I really enjoy conan, however I know the AO starts to drop qaulity really badly soon and I was wondering when I should stop watching AO. I have heard around 400 it stops being decent is that the best time to stop watching them or else you will really start to grow tired of the series (like a friend I know). I know that there are good AO like the seance case (which I ended up seeing) are worth seeing however most times people say you need to see X case.

SO basically when do the AO episodes go down hill? and what episodes after then are actually worth seeing?

SO far the consensus is Skip the one part AOs only (except 376, 418, 426, 437, 471, 527, 539, and 634) assuming you have the time to do so

[Vylash]

stop right now and skip to 603-605

[dilbertschalter]

the difference for AOs is smaller than it is for manga based episodes, don't bother with skipping them.

[doublemoonlight]

if you are short on time don't bother with AOs at all.

[Wakarimashita]

Skip the one part AOs only (except 376, 418, 426, 437, 471, 527 and 539). 2 parters (and specials) are usually decent and sometimes even good, so I suggest watching those.

[ranger]

If you want to catch up really quickly, skip all the AOs; I think there was a pretty good around 410ish, where it has Shinichi's parents in it (and Ai!), but I mean..some of them are really bad, especially in the 500's. 

[Kei.Akai]

Skip the one part AOs only (except 376, 418, 426, 437, 471, 527 and 539). 2 parters (and specials) are usually decent and sometimes even good, so I suggest watching those.

I add 634, too...