Forever Red was a better episode. There was a stronger feeling of heroism IMO and a greater threat (Serpenterra, Machine Empire) compared to Psycho Pink.
While "Power of Pink" had the 'sacrifice' thing, thats really all it had.
Okay, compare that with the other Red Ranger episodes I listed:
"A Face From The Past" was more about Mitchell's heroism shaping Carter, its overall a more relevant episode to this theme than "Stranger Within"
"Fight Against Fate/Destiny Defeated" is 100x better than "Stranger Within," some of the best episodes of Power Rangers and they showcase the heroic struggle to change ones fate.