Then you have to cast them, so you'll want to run the mana for them
There was definitely a period of time where I noticed my play patterns with the card were actively sabotaging my land drops later in the game, and during the early days of Commander, where big, splashy spells were king, I wrote Land Tax off as being more trouble than it was worth
Seat of the Synod is the king of the colored lands, because blue is the color that works best with artifacts, and Vault of Whispers is second because of Disciple of the Vault, but all of them have joined the fun at one point or another
These references aren't totally obscure, but I also picked ones that aren't such popular knowledge that even people who haven't played the games probably know about them, like Sephiroth killing Aerith
Tinker Bell Very Clever Fairy works amazingly in an item deck, helping to ramp if a little late in the game
For instance, Sephiroth, Fabled SOLDIER allows users to sacrifice a creature to draw a card when he enters the field or attacks