So I did 7 batches for my own wedding party:
2 x hefe
1 x IPA
1 x saison
1 x dry cider
1 x dunkel
1 x barleywine
The saison was the first to go, followed very closely by the IPA, followed by all 10 gallons of the hefe. There was a little bit of dunkel and a little bit of cider left, and about half the keg of barleywine. Granted the barleywine was over 13% ABV and I didn't tap it until dessert was served.
Most of the crowd was very into beer but a lot of people were not. Hefeweizen is always a good choice since most people like it: beer newbies, BMC lovers, craft beer nerds, people looking for something fruitier, etc. No decoction mash needed, I've never done one and I've brewed many batches. Toss in some melanoidin or munich malt and you're good to go.
Saison and IPA were incredibly popular with the beer geeks, dry cider was great for wine lovers and gluten-free folks, dunkel was fantastic for people that wanted something a little darker. This was August so I didn't want to do a stout/porter, and I wanted something a little more exciting than brown ale.
I wanted to have a nice variety of styles so everyone could enjoy something, I wanted to stick to traditional styles and I knew I wanted at least one lager. If I could go back, I wouldn't change a thing.
You can also buy a 2.5 gallon keg (AIH has them for like $70) and do something fun like a keg of gin and tonics. I did that and the entire thing was gone. You can also buy a keg of local/craft commercial root beer for the kids. I did that as well and it was a big hit with non-drinkers, adults and kids both.
The logistics of the brewing (timing brew days, fermentation chamber use, kegerator space, plumbing, etc.) was a good bit of work so just make sure you have a plan for every single thing. Have extra CO2, have an extra party tap just in case, etc. My party was at a private residence and I had all kegs in the kegerators a full 3 weeks before the party to make sure they were carbed/settled.
I had so much fun with all the brewing, it was awesome seeing everyone get drunk off my creations and I got nothing but compliments all night which made me pretty damn proud. Feel free to hit me up if you want to talk more!