I installed Snow Leopard shortly after its release, and overall I have really liked it. The one thing that has been driving me absolutely bonkers was the fact that now under Snow Leopard, Finder automatically resets its columns back to a narrow width. If I had hair, I would have been pulling it out over this quirk, but luckily I have finally found a fix.
Let me explain the "problem" and then I’ll show the simple solution. When using Finder, my preferred view is the "multiple columns." I’m not sure there’s any specific reason why, but that’s just how I like to navigate. Prior to Snow Leopard, the columns would resize themselves in such a way that you could see the names of the files listed in each column. Times were good, people were happy.
The "problem" is that when I installed Snow Leopard, Finder began making all columns extremely narrow by default, with no apparent option to change this setting. Yes, it was nice to be able to see more columns, but it actually caused more problems than it solved. My office uses a standardized naming method I use our client files (YYMMDD File Name), which results in everything being listed in chronological order. Therefore, all I could typically see as part of the date with little to no file name. The image below shows how my "Applications" folder looks using the default column width. Again, this can drive one mad in a very short period of time. (Note: I realize that many would argue that it’s a very short trip for me, but I digress…)

Since I am male, I am hesitant to ask for directions, so I tried every trick I could think of to attempt to change the default size of the colums, short of voodoo or black magic – though those options were becoming more appealing as time passed. Finally, I gave in and conducted a Google search, and voila – found a solution. To set a new default column size, you simply hold down the Option (Alt) key while sizing the columns in Finder. Then, when you open a new Finder window, the default size is changed going forward. The image below shows the same "Applications" folder from above after the columns have been resized.

Thanks to Geert Vanderkelen of the Some Abstract Type! for his post on this topic.