Just as Cephalid Coliseum had its day in one of my Discard decks, so too did Ill-Gotten Gains (Urza's Saga). Sometimes there may have been a pairing combo between the two. Not a specific combo like you'd normally give the attribute to, but just that it would potentially allow me to fetch the spent lands from my graveyard to use again.
With my Discard deck, I didn't mind that Ill-Gotten Gains allowed my opponents to get card from their graveyards. All that did was feed their hands, allowing me to force them to discard and take more damage. As explained above, being able to pull cards I had already used from the graveyard served me much more reliably. If they had large hands they had to discard (hopefully causing them to take damage), that was just a bonus.
There were a handful of these "discard hand" cards that I played with. Some forced players to draw cards equal to what they discarded, refilling their hand for me to target. If paired with enchantments that damaged opponents for each drawn card, you would gain even more value.
I do believe I played with Ill-Gotten Gains in a zombie/reanimator-like deck, along with Ichorid (Torment). All the details are a bit hazy, but I'm sure it had some graveyard recursion theme. When I was building decks at the time, and playing casual, the concept was still relatively new to me. Zombies and aggressive graveyard manipulation decks weren't really my forte. In fact, having any creatures in my decks was fairly rare, preferring those with more control elements.
I only own a playset of regular Ill-Gotten Gains (and seven regular Ichorids), and I had (have) them in toploaders, but their monetary value has dropped substantially from when I first organized my collection. I thought it was a really popular card, though possibly niche. I guess it's either been replaced or the archetype died. I'm not even sure which archetype it predominantly belonged to, because I know Discard specific decks aren't very tournament worthy.
I still really like the card (both of them actually), so maybe it would be a good time to snap up some foils which were printed in the 2014 Conspiracy set.
Have you ever played with Ill-Gotten Gains? Do you know what deck it used to be played in competitively? What are your thoughts about Ichorid? Have you played with Ichorid in any specific types of decks?