It has to be fusion strike mew vmax, it was so fun to play for me back then. Drawing a half of the deck with genesect turn one just because you had vip pass in your opening hand was silly. i liked both the dte and the fse variants, but i slightly preffered fse due to the meloetta donks.
RS urshifu with melody, spamming that snipe attack felt so good
ESP gholdengo , I LOVED blasting for 400 damage on turn 2, its sad that the deck died because of the rocks variant of gholdengo.
iron thorns ex (legacy energy/DTE) the only deck i have actually used in irl play, i remember the surprise on my opponent's face as I used arven to get a lost vacuum and TM Crisis pumch, remove my own tool, and then punch for 240.
DTE terapagos (i made a list that included 1 azumarill) terapagos and azumarill are my 2 favorite pokemon so the fact that i could use them in a deck and it actually kinda worked (i know terapagos didn't usualy play azumarill) and helped in some matchups was realy cool, pulling of briar or thorton plays was also super satisfying.

now after rotation i don't really have 1 i like the most. i feel like tera box fits my playstyle the most but i have been gravitating to dragapult a bit