Brussels sprouts are never slimy when they are prepared properly. You have to buy them fresh, never frozen, use them soon after you buy them, and steam them until just tender. Never boil brussels sprouts, and don't over-steam them. Then you eat them with lots of yummy butter and salt, or put them in a nice marinade of red wine vinegar, a little oil, some basil, thyme, salt and pepper for an hour or two and eat them at room tempurature.