I don't think that there are any browser versions for 10.6.8 that are fully supported anymore (Safari, Chrome, or Firefox). There are browser versions for OS 10.8 (two OS versions newer than 10.6)…that are no longer fully supported.
Your MacBook 4,1 is from 2008…and unfortunately the maximum OS for it is 10.7.5. You really need at least OS 10.9 (Mavericks) to get a browser version that is fully supported at this moment (July, 2016). But as mentioned…a MacBook 4,1 cannot run OS 10.9.
For what it's worth…I have a perfectly working Mac Plus from 1986…and there are no fully supported browsers for it either.

Having a fully functioning computer (regardless of age)…unfortunately is not a prerequisite for being being useful or compatible forever & ever.
Eventually older hardware becomes obsolete…even if it does still work perfectly.
HTH,
- Nick
p.s. Just in case you meant MacBook Pro 4,1 (and not a MacBook 4,1). A MacBook Pro 4,1 can run the latest OS version (10.11 El Capitan). And if this is the computer you actually have…you could upgrade the OS & get newer fully compatible browser versions.
