Verbatim are excellent disks. The ultimate deciding factor is the type of dye used on the disks - Taiyo Yuden is accepted as being the pinnacle of dyes but the disks are expensive. verbatim use a dye which name escapes me right now (might be Ritek003) but is considered excellent also and the disks are very reasonably priced.
www.bigpockets.co.uk and
www.blankdiskshop.co.uk are brilliant sources for quality media at bargain prices. -R media is accepted as the universal media which will play on pretty much everyones standalone players where as +R is the outsider as mentioned but considered to be the tougher brother. For important storage you could always use a quality +R disk and then transfer that data to a -R disk if you ever needed to.