Sapphire Low Profile Ati 4650

Would the Sapphire Low Profile Ati 4650 ( work with a Dell Demension 4600?

Simply put, no. Your particular model uses AGP; not PCI Express. Do you have the 4600 or the 4600c? The first has a bigger case than the latter. This will determine whether or not you need a low profile card. What are you wanting to do/play with this kind of upgrade? Your system is ancient by todays standards. If you are wanting to play anything more demanding than the Half-Life or Counter Strike or games of that nature, basically all recently released games. You won't have the best experience using that system. Might as well save and build a better system.

4600 and i want to play guild wars, WOW, Fallout 3, Sims 2 and/or 3.

i have wondered what the best AGP card is to date today?
isn't it the HD 3850? or is there something better than that?

I had this card last before I made the leap to PCI Express:

It was a great card. I never had any problems with it. With the exception to Fallout 3, I think you would be able to run the rest of those games at max settings, assuming another part of your system isn't being a bottle neck. I don't play any of those games but I hear they can be pretty CPU intensive which would probably limit your gaming experience because I don't think you would see the full potential of that card I recommended. It is the best as far as AGP goes. I assume everything in your 4600 is still factory. If this is the case, I would just advise you to just save your money and build a new system. I would say at the minimum, you would have to upgrade your power supply to provide the required power to the card mentioned above. I could go on about other stuff but I'll stop for now.

Personally, I like to play games as they were meant to be played. I find that I don't enjoy them as much if they aren't played in full detail. My advice to you would be to go ahead and just save up some money. You could probably build a good mid-range AMD system for about $500 using some of the parts you already have.

You could get this card with your current setup:

But I don't think it would run all that well with what you have. Its all according to how much you want to spend. I would really consider just saving for a new build as you would just be propping up a dead horse by upgrading your current. It's up to you though.