Which would you rather be chosen by; Mjolnir, Green Lantern Ring, The Wizard Shazam, or Galactus?
Be chosen by Mjolnir and become a Norse thunder god, or maybe by a GL ring and be a space cop that glows. Or maybe touch the staff and say the name of the wizard Shazam and become his protector of the Earth from magical threats. Or you could accept the burden from Galactus and become a herald who basically is a space God onto innocent planets' populations to feast on.
Which would you rather be chosen by?
The G.L. ring. It provides high levels of protection, attack energy, space flight of universal level. Holy Molly! Classic Mjolnir with the power of Thor would be fantastic as well and more powerful than the ring. The current version however may be my own worst enemy and may desert me for any reason whatsoever. This version drops down to last in a hurry. Still the difference is personal preference on my part. Shazam would be great just not quite on the level of the first two in the fun category. That critique may be why I would choose G.L. over Mjolnir as well. The Power Cosmic sounds great but going by your stipulations I would not like taking Galactus around the universe eating planets. Wouldn't like having my memory altered either though if it happened I guess that objection would be moot. If freed then it moves to the top of the list.