"Aoibhinn" basically means "delightful" or "extremely enjoyable", and in the construction "is [adjective] le [person] [noun phrase]" (e.g. "is aoibhinn liom Montague", "is fada liom uaim iad", "is beag liom é"), although the [adjective] describes the [noun phrase], it also affects the [person] introduced by "le" in some way, often emotionally (so the examples above could be translated: "I find Montague delightful", "I miss them", "it is too small for me (in my view)"). So I would say that all the possible translations you listed are correct (except No. 2 where the way you have written it you have the subject and object the wrong way round, it would be more like "for something to be delightful to you", but I think that's probably what you meant anyway). There is no absolute translation; the way you translate it into English depends on the context and the style. "I find the place delightful" is quite a literal translation of "is aoibhinn liom an áit", but in English it sounds rather 19th-century; "the place is delightful to me" is even closer to the original but sounds even more antiquated in English. In contemporary English the best translation would probably be something like "I love the place".

@Naoise: "carad" is the genitive case of "cara", so "teach mo charad" means "the house of my friend / my friend's house". "Áthasach" means "happy", which is derived from "áthas" = "happiness". In Irish there's a distinct preference for phrases like "tá áthas orm" rather than "tá mé áthasach", though that is also correct. "Tugaim áthasach ó..." doesn't really make sense, it would be better to say "Cuireann ... áthas orm", if you want to use "áthas", but Shawn's phrase is better.

That sentence means I love the simple things what you want to say is tugaim áthasach ó na rudaí simplí i mo shaol I personally don't know the word for pleasure but áthasach means happiness

This sentence almost makes sense chuig means towards , no d in cara and it's le mo chara with my friend