Funnily enough I think my best wedding breakfasts/meals have been traditional English/European hotel style which is not normally my thing, but done really, really well with an eye to what works best when catering for numbers rather than what's nicest as a meal in a vacuum - so cold starters (one was sharing boards of charcuterie, cheeses, olives etc but several per table and very generous to avoid the greedy-guts issue and the other was a choice of prawn cocktail, pate or burrata), mains that were not timing dependent (one was braised shin of beef in a red wine sauce, the other was some kind of slow roasted lamb). Can't remember which way round but one had a very luxurious mash as a side and one had a potato gratin/dauphiniose. And a nice choice of traditional puddings (crumble/sticky toffee/lemon tart/some kind of chocolate confection) is my recollection.
My normal issue with less good hotel type catering is that the meat is always cold and/or dry by the time it gets to you, especially if you're at one of the 'back' tables that get their food hours after the top table (often in the case of things like chicken it probably started off dry in the first place) and also that it's clear they've cut costs by using poor quality ingredients, so to get this kind of food to work I suspect you do have to spend ££££. In the case of the cold/dry issue it might not always be obvious to the bride and groom how bad it is as probably when they did the tasting the food would have been fresh and ofc on the day itself they get theirs first....
If you're on a bit of a tighter budget and have a lot of people to feed I think things like curries or hog roasts or buffets work better (if it's an element of self-service though do over-cater particularly on the veggie/vegan items as some people will take more than their fair share!) - BBQ I'm a bit dubious about, depends on your wedding size and venue really, the only wedding I've been to that managed it successfully for 100+ guests was a Greek one so they had specialist equipment, and even then they got really lucky with the weather, every single other time I've had BBQ at a large UK wedding (not talking about a small get together in the back garden ofc) again the meat has been a bit chilly and rubbery by the time the back of the queue gets served (to say nothing of the guests getting frozen in the queue and/or the poor chefs getting drenched in the rain!). And the sides can get quite decimated too so again some over catering required.
Food vans are def worth looking into although again, if it's a big ish wedding do think about how long is it going to take to serve all your guests/capacity. I've been to a few weddings with these (I go to a lot of weddings thanks to DH's huge family) and the food can be really nice but again always a lot of queuing as the pizza van slowly churns out two pizzas every 5 mins or whatever. Even if it's a token system with more than one type of van there's usually some that are more popular and build up a long wait time (DH got quite hangry queuing a hour for what turned out to be a very mediocre burger at the last 'food van' wedding we went to so maybe I'm biased on that front!). TBH if we get fed something hot and in a timely fashion I'm pretty happy, I don't look to weddings to provide a gourmet experience personally (even though I'm aware with venue hire etc the bride and groom are probably being charged as though it is!).