* Cha dìochuimhnich mi a-riamh: This is a very literal translation and probably the closest. "Cha" (not), "dìochuimhnich" (forget), "mi" (I), "a-riamh" (ever).
* Cha chall mi a-riamh: This translates more literally to "I will never lose [the memory]," implying a more precious and cherished memory. "Chall" means lose.
* Cumhaibh mi gu bràth: This translates to "I will remember forever," which implies a continuous remembrance rather than simply a lack of forgetting. It's a more poetic and emotional choice.
The best option depends on context. For a general statement, Cha dìochuimhnich mi a-riamh is a safe and accurate choice. For a more emotionally charged statement about a cherished memory, Cha chall mi a-riamh might be better. For a more poetic and enduring remembrance, Cumhaibh mi gu bràth works well.