Absolute worst is cash poems accompanied by a sort code and account number.
Also hate gift lists when the bride announces on a night out a few weeks before the wedding who has bought what so far, which makes it clear how much people have spent and who hasn't bought anything yet. I want my gift to be a surprise for the wedding, not commented on in advance.
I always ignore lists and poems now and either buy something more personal or donate to charity (mainly when the rhyme seems especially grabby and emphasises how much they already have....had one that actually complained about having 2 houses worth of stuff now they had moved in together)
DH and I have also decided not to go when we're on the B list (evening do only) unless it is local. Last time, we had to fork out for petrol, the hotel, taxis to the venue all to sit in a cramped overpriced bar and barely saw or spoke to the bride and groom.
We took all this into account for our own wedding, got married early evening, followed by dinner so just one set of guests. Didn't ask for cash or any presents but did get asked so in the end, we picked a charity each that was close to our hearts and suggested people made a donation if they wanted to give something. We ended up with a mix of charity donations, vouchers, cash, a couple of personal presents and a few people who didn't get anything. And that was all fine, we genuinely did appreciate people giving up their time to celebrate with us and didn't mind if we received anything or not.