I like it. I don't love it, but it's pretty without being super frilly. I can't believe how much I prefer it to Lila/Lilah. There's something about the "De" that gives it a whole different vibe, in my opinion.
Lila sounds a bit sickeningly sweet, but
Delilah is strangely cool and not cutesy.
Delilah seems like a hard name to pair with middle names. I'd avoid anything with L's and probably anything that ends with an 'a'. Some random suggestions...
Delilah Pearl Delilah JadeDelilah JuneDelilah RubyDelilah Chase (probably my favourite)
Delilah Rae /
RayDelilah Mae /
MayDelilah Bridget