A.C.
I've never put mine in water. That doesn't mean it's wrong as much as me probably just not knowing. I just use it within a few days from buying, as I do with most produce. It's never been an issue for me though, not putting it in water.
Most often, I put it in the steamer and cook it until it's soft enough to eat, but firm and even a little crispy, and then season with just a little salt afterwards.
We really like it grilled or broiled though, with sea salt, black pepper, and just a little oil when we're eating steaks.
One of my favorite ways to eat asparagus is in chicken. I'll hammer a few breasts until flat (chicken between 2 sheets of wax paper), then I'll put in 2 or 3 asparagus spears, some thin sliced mushrooms, a little bit of rotels, some shredded mozzarella cheese, and some chopped up marinated artichoke...roll or fold the chicken closed with a couple toothpicks to help keep it closed, rub some egg around the chicken, and then dredge in Italian bread crumbs. Brown on all sides, then bake until cooked through.
You can also include them in omelets (with mushrooms,onion,tomatoes, a little parmesan or whatever)... or roasted in the oven with some parmesan, or in a pasta.