[Matrixbeast]

Hmm, I've grown rather fond of the recent Red-Eyes fusion, Meteor Black Comet Dragon. Inferior to the other Red-Eyes fusion, Archfiend Black Skull Dragon? Yes, quite. Looks hell of a lot cooler? Yes by a mile. I'll summon this bad boy over the other just because he just looks so damn cool

For Synchros, I gotta go with the old gold standard, Brionac, Dragon of the Ice Barrier. No one used Ice Barriers, but 2 of their 3 dragons, Brionac and Trishula, saw major play because of how useful they were. Brio in specific, and I love the thing. Sucks that it got banned...
(I also have some fond memories because when I played in tournaments, I ran Plant Synchro during Brionac's hay day, so I used him quite a bit )

For XYZ, hmm...A little more difficult. I guess I'll go with one of the lesser known, but quite useful ones. Number 37: Hope Woven Dragon Spider Shark. Only really useful to water monsters, thankfully I ran a water deck, Gishiki, so he saw quite a lot of play from me due to his ability to summon a water monster from the grave when he was sent there, himself. Made for ritual plays a lot easier~