for convience, durability, and portability... a metal pipe.. just a little bitty one, but not a one hitter.. you know those basic bowls that have a good 5-9 hits in 'em depending on how you pack it or w/e...

i perfer glass, but you can't argue the durability of metal... it's cheaper too, and iv'e never gotten attatched to a metal pipe so if i lose it or something, it's not like i feel bad... glass pipes have personality, metal ones you just replace, probably even get one that looks the exact same.