LuminousBeing said: "Depends on what you like. They're very different shows that provide very different experiences,
"Bandstand" has a (fairly homogenous) big band score, a "Lifetime Movie"-esque plot, great dancing, and Tony-winning swing choreography. Decent performances by the two leads.
"Miss Saigon" is a classic with a gorgeous traditional Broadway score, a harrowing and controversial storyline, and no big "dance" numbers ("Morning of the Dragon" notwithstanding). Outstanding performances by the two leads.
Personally, I love "Miss Saigon" and am able to overlook its problematic elements because the score and story sweep me away each time. I found "Bandstand" to have a couple effective moments, but overall to be a fairly bland night at theater. For me, it's not even a contest: "Miss Saigon" without question. But not everybody is like me; some would rather have a light and fun evening than see something heart-wrenching. And that's fine. :)
Hope that helps!"
As Luminous said, they are two very different shows. OP, you didn't give any indication as to what appeals to you, so it's difficult to make a recommendation (one man's meat is another man's poison).
Personally, I also prefer Miss Saigon by a mile.
==> this board is a nest of vipers <==
"Michael Riedel...The Perez Hilton of the New York Theatre scene"
- Craig Hepworth, What's On Stage