PBR, Miller High Life, it's really your choice. If you're going craft beer, a malty marzen like Burke's Alewerks' Oktoberfest would both delicious and seasonally appropriate. Plus, it might impress the Wisconsinites. Optional: Brown Sugar, Golden Brown Mustard, Sauerkraut.
Bring the water and brats to a boil and then reduce heat to a simmer. Let simmer for 10 minutes. You can boil and simmer the liquid and brats either inside on a stovetop or outside over a grill. This parboil step helps cook the brats evenly throughout so you don't have any raw spots in the middle!
Beer Pairing Suggestions Since pork and sauerkraut is a Germanic dish, beer is its natural companion! Figuring out which beer works best, though, isn't so natural. You will want a medium bodied beer, neither too dark nor too light. Avoid pale ales, blonde ales, and weissbiers.