There are also quite a few odd-denominational chips used for drop chips at cardrooms and poker rooms. Foxwoods, Turning Stone, and some of the California rooms use them. These are special because they mostly won't leave the poker room and a normal player doesn't use them.

And speaking of California rooms, they will often have denominations such as $3 and $4 to be used for limit games like $6-$12, $8-$16, or $9-$18 structured game to make it a 2 chip 4 chip or 3 chip 6 chip game. Also denominations such as $10 and $20 for poker rooms where they spread higher limit games such as $10-$20, $20-$40 (to make it a 1 - 2 or 2 chip 4 chip game).

Not to mention the $2.50 chip used at many places. Seems to make sense for games like BJ where a 3:2 payoff requires an odd-denomination, but isn't used in any of the other games.

I don't think you can consider these "special chips" because they can be used at other games (where applicable) - meaning you can use the pink chip at a let-it-ride but they may require two (in which case they replace it with a $5 and put it in the rack). The same holds true for the yellow chips.