title_body: What would be the most accurate character to use to transliterate the 'e' sound in 'bet' to the Arabic alphabet?
upvoted_answer: I don't know any language written using the Arabic script, but as far as I can tell the most common approach across languages for representing /e/ is using some variant of ي.
  Somali uses ئ, Pashto and Uyghur use ې, and Kurdish, as you mentioned, uses ێ. The Jawi script used to write Malay even uses ي for both /i/, /e/ and /ɛ/. Urdu uses two different symbols, ے (which is based on ي) and ہ (which isn't).
  I can't really speak in terms of how recognizable any of this would be to Arabic-speakers of course, but since multiple languages that needed an /e/-like letter reached for ي, it seems reasonable to suggest that approach.
  But things are never simple - ە is also quite common. For example, you mentioned Kurdish which uses it to represent /ɛ/ (which is not /e/, but pretty similar), and Persian also uses it for /e/. And as I said earlier, Urdu does use ہ (based on ه), though I believe ے is more common (except word-intially, where it can't appear).
  It seems to me like some twist on ي is the most common across languages, but which one to pick is not obvious (though I expect they'd all be about equally clear to someone who isn't already familiar with one of them). ە is more uniform, but might be a bit less common, and in languages that use both (like Uyghur and Kurdish) it seems that the ي variant usually represents /e/, while ە is something like /ɛ/.
  So, I'd probably suggest ێ, but either option seems reasonable.
  Source: Arabic script § Additional letters used in other languages (Wikipedia) (and various language and script articles mostly linked to from there)