why do you say your "processor sucks"?? your processor is only one of several factors which determine system performance.
when was the last you formated & re-installed windows??
-if the answer is never, then that could be the main reason why your system is slow. if it performed well when you bought it but seems slow now then it just needs a good cleaning (software-wise that is). the best way to do this is to back up your important data, then format your HDD and re-install windows (windows will format the drive for you during the installation).
your processor may be slow compared to today's offerings, but that doesn't make it too slow to use. it's more than capable of surfing the web, email, office programs, and mild gaming.
if you still want to upgrade then I'm afraid you won't have many options with that motherboard. socket-754 is an old platform and finding new processors for it may be tough.
the only model that newegg sells is the one you already have lol. you can probably find something on eBay or if you check a few more stores.
but to be honest I'm not sure it's worth upgrading a socket-754 system. the fastest CPU you can get for that system is an Athlon64 3700+. while it would be an improvement it would not be huge. you'll still be limited by socket-754's slower hypertransport BUS, lack of dual channel memory support, and lack of faster CPU models to use with it.
my advice is: unless you can find a s754 3700+ cheap, then hold off on the upgrade until you're ready to upgrade the whole system. that would include at least your CPU AND motherboard at the least. if money is tight then you could get away with upgrading to socket 939 which will (on certain motherboards) allow you to keep your AGP video card and DDR memory. socket 939 is also discontinued but there are alot more processors to choose from and they are much faster then what's available for socket 754. don't go Intel unless you've got the money to get a Core-2 system (which will also require a new video card and memory)
good luck :wave: