@DavidSark - yep. I don't have any SLRs. I shoot all rangefinders.
Depends what you want to shoot. If it's digital, then all you have is Leica. If it's film then you need to choose between 35mm and medium format. Zeiss have just stopped making their famous Ikon rangefinder (35mm), so it could be worth picking up one of those. Bessa, don't bother. Leica again are classic. You can pickup Canon and Nikon rangefinders. Unsure what they are like. If medium format is more your game then the Mamiya 7 holds incredible resolution and kicks the sh*t out of any DSLR on the market.