Oversoul's list sure makes my work easier. I'd almost agree with Dark Ritual. You have to know that I was most actively playing magic in the time between Ice Age and Visions, and starting again with Nemesis (really). The second time around it was much clearer that DR is the powerhouse that it was, I mostly used it to power out first turn hippies or hymns. I've never played it in a combo deck, nor have I ever played a first turn Negator. If I had, DR would be on the top of my list.
As would Sinkhole, if I ever would've gotten more than 1. Around 2000 I figured I wanted to play vintage, and that I wanted to play Pox. I knew Pox, and that card is exactly how I want to play magic. The deck wasn't really good, but playing null rods, hymns or sinholes from a dark ritual was reasonably solid. I've bought every sinkhole I ever saw in a dutch webstore. That's why I still have only 1
By the time I gave up there were more showing up (probably people quitting vintage or moving to a better deck) but they were twice the price I was expecting to pay for them (which was actually twice the price I was willing to pay, so I'd be paying 4 times more than I'd like).
My favorite common could've been Duress, but that card wasn't around when I started playing. Not long after I started playing I ended up with a deck with rituals and hymns (and every creature with protection from white, fyi, stupid stp). I loved playing Hymn to Tourach, I still do. Back then I saw ritual more as an enabler instead of the huge tempo boost that it is. But just for the effect nothing beats Hymn to Tourach for me. To see the your opponent change from happy with his opening hand to terror from the possible random discard is priceless. Yes, I might be a griefer, but if this shouldn't be part of the game then they shouldn't have included black. Duress does something similar, but the randomness of hymn is what it makes so fun to play. Hymn ftw!
As a bonus, my most hated common: Brainstorm. Dumb blue players hiding their valuables from my discard and taking forever to look at their cards and putting them back
