In my opinion,Firefox 3,though it takes more time to start than google chrome,its performance is that what pleases me.Chrome makes my 7 year old computer crawl on its knees with 100% CPU utilization...
I would say,with minimum resources,U cant beat firefox..I have already tried a lot of browsers including opera and safari...
The worst browser i have ever used is safari..
By the way my system configuration is..
Pentium 4 1.6GHz
512 MB 266MHz RAM
40 GB 5200 RPM Samsung HDD
Sony DVD-ROM
Samsung DVD-RW (Only Brand new component 1 month old,had to hunt around 5 shops to find an IDE Burner...
)