I've been digging through my reference books and Google searches, but I'm not getting anywhere with this.
For "Only I [do X]", can the subject of the sentence simply be 私だけは?
私だけは電車で魚を食べます。
"Only I eat fish on the train."
And could that be done with an adjective like 好き or ほしい?
私だけは天ぷらピザが好きです。
"Only I like tempura pizza."
For my final act, I'm going way out on a limb here, but how would I say "I am the only [Y] that [likes X]?" This is the mess that I came up with:
「ドルアーガの塔」のことが好きなアメリカ人は私だけです。
I am the only American who likes The Tower Of Druaga. (Or more literally, "As for Americans that like The Tower Of Druaga, it's only me.")
How wrong is all of that? Because I'm pretty certain it's not correct.