My favourite pose would have to be Virabhadrasana II! I would say that it’s definitely one of the most signature poses of yoga, and probably one that people would be likely to associate to yoga even if they’re not practitioners.
Getting into the pose was never really a challenge, but it was the alignment and endurance required to hold the pose that gave me great challenges along the way. Especially in a hatha class, my legs would be shivering uncontrollably after 10 seconds. Yet the teacher would still calmly tell us to get our front thigh parallel to the ground, which was impossible!
But gradually overtime with practice I found out the trick to the balancing of the weight placement, and adjustment of the shoulders/scapula to prevent too much use of the deltoids. (My arms were always as tired as my legs if not worse!)
Going into other poses from Warrior 2 is always fun too as the stance is very versatile, and you can pivot your limbs in most directions. Having many variations also keeps things refreshing, and holds the saying “there is no end to an asana” true to its meaning.