Conecting PS2 to monitor...

I recently bought upscan converter 2 and connected my ps2 (slim version) to monitor, Samsung SyncMaster753DF. I noticed that the quality of the output significantly decreased compared to the tv connection. I'm thinking of buying an s-video cable for ps2. Would this help to bring the quality back to something close to tv?

Just get a TV card. A good one.
It's always going to look shit on your monitor, seeing as it's made for a much higher resolution.