Im getting a new graphics card, I now have a NVIDIA 7800 GFX (256 version) and im running it on a dell WPF2407 24 inch LCD at a res. of 1900x1280 (or whatever the number is close to that res). My question is this: I read the reviews on this site and I want to get the 8800 GTS (620 version). Would this be sufficient to run graphic-intensive games (Oblivion, LOTRO, etc.) with all the higher settings? The card I have now struggles. Thanks.

To turn up the eye candy at 1920, you should really get the 8800GTX.  The GTS 640 is great, but will still struggle at that rez if you wanna jack up the details, AA, AF, etc.

Not so,I play all games maxed settings 1920 x 1200 just fine... But I will be using my step up program next month for the GTX. Games play just fine now but in 6 months with crysis out I want to be sure it will run a little better than fine.

In that resolution i think that you better go for the 8800GTX or wait until Xmas for next generation cards.

Ive got the 8800gtx and at 2048x1536 it can struggle with oblivion and lotro with everything turned up at times, I do think you will find the GTS underpowered for your resolution.  
 
Im considering the jump up to 8800GTX SLI for 2048x1536 gaming!