Okay. You're not supposed to have favorite chords, at least not in the abstract. Both Babbitt and Feldman would have agreed that it's about the context in which the chords are heard, what comes before and what follows, what repeats and what just passes by. It's about the timing, the duration. It's about the voicing, registration, density, orchestration, doublings, dynamics. It's about the accents. It's about the time of day. It's about the weather. It's about having had a bad day at the office, getting a flat in the car, or losing your house keys. It's about fresh squeezed orange juice, and your daughter laughing for the tenth time at the joke about mayonnaise in the refrigerator. It's about going into a two hand showdown with a pair of fours, a prayer, and an opponent with a nervous tell.
But it's not like that. We have associations, tastes, habits. We have, and play, favorites. I used the first chord above, modulating to the fifth above via the two common tones, in my very west coast minimalist piece Multnomah Riffs in 1977, again in a piece for sine waves and crosscut saw, School of Levitation (1983), and most recently in my fourth string quartet, Autumn (2006). The second chord has figured in a number of pieces, often cadentially, including a chamber orchestra Passacaglia (1982), and the Passacaglia that ends my string trio Figure & Ground. And the third chord, which goes by a number of names in the theory literature, but I think of as a subharmonic seventh chord, appears probably too often for my own good in a number of pieces. I've used each of these chords in a numbers of temperaments and in just intonations.
Try as I might, I've never been able to erase any of those associations, nor abandon those tastes and habits. A fault, perhaps, but one with which I will have to live.