Holy water is equally unpredictable in its usefulness. However, the way vampires sizzle when it does work is worth carrying around a little squirtgun just in case. Vampires are not immune to conventional weapons, it is just a question of wear you hit them. The key is to either sever the head or rip the heart apart. Some lab studies have shown that explosives and high caliber ballistic weapons can be as effective at this as the traditional wooden stake and bowie knife.
Fire is also a handy tool.
Pentagrams, holy symbols and garlic are usually handy tools for protection for vampires. However, they tend to make one's laboratory look like a new age bookstore. Popular theory holds that they aren't allowed to enter a structure into which they haven't been invited. Sounds nice, but also a little hokey. Another cornball theory is that they can only sleep in a coffin filled with earth from their homeland.