I listened to all the Pablo Honey and The Bends singles that are available on Google's service, and to be honest I didn't really like most of them. Many songs were very simple or felt like lesser versions of their album counterparts. Not saying they are bad, but there's nothing essential there to me. That said, I'll make sure to give them another chance eventually.
To be fair, I hated that album and OK Computer when I first heard them 2 or 3 years ago. This could have been me, giving the album the lowest possible rating and thinking it was worthless. Maybe it's a matter of training the ear by hearing similar stuff, or tastes changing with time or something like that. No idea, but when it eventually clicked, it was good.
The Bends b-sides you can definitely skip (except for Talk Show Host - one of their best tracks) and Pablo Honey even moreso.
Honestly, they get really good around Amnesiac, the b-sides for which are among their very best work (see: Worrywort, Cuttooth, The Amazing Sounds of Orgy, Fog)
At bare minimum I would make absolutely sure to catch these:
the Amnesiac ones I mentioned above
Gagging Order, from Hail to the Thief
In Rainbows disc 2 (whole thing, especially Last Flowers, Go Slowly, Up on the Ladder)
Staircase
The Daily Mail
These Are My Twisted Words
The Butcher
Supercollider
Spectre