OK, so nobody is gonna mistake either "Frankie and Johnny" and "Paradise Hawaiian Style" as being among his best work. That said, both are good albums, if they are accepted on their own terms (1960's pop).
"Frankie and Johnny" is my favourite of the two, with is slightly unusual arrangements that include elements of the time that the movie itself was set in (1890s), although the songs sound more like something from a "Looney Tune" short than authentic music of the time. Still, Elvis tries his best, and the end result is fairly listenable, if cartoonish music, and few of the tracks are downright bad.
"Paradise Hawaiian Style", on the other hand, is basically the same thing, except with Hawaiian music. The tracks here are a mixed bag, with some verging on unlistenable (Such as the Grant/Baum/Kaye compostion "Queenie Wahine's Papaya"), although as usual, even on the songs which Elvis himself may not of liked, he still sings them very well.
Overall this CD may not rank among anyone's favourites, but with Elvis Presley's excellent singing, plus support from some of the top musicians and songwriters at RCA at the time, this is certainly a worthwhile listen.