The danger in wanting to be God’s favourite is that it may stem from sinful motive to be superior to others, a bit like James and John in Mark 10. That’s not to say we shouldn’t want to be the best we can be, but it’s not to be better than the next guy. We are to be vessels of honour, meet for the Master’s use, i.e. be my best for Him.
Christ deserves that you give to Him your all. You don’t deserve it, and you don’t have any right to be better than others to be esteemed God’s favourite. But Christ deserves our best regardless of our position, and all motives must be for His glory and preeminence.