Well, I never played ME 2. I only started to play the first one but I didn't enjoy the beginning so I left it at that. Years later a friend told me about how cool this trilogy was so I decided to just go for the last one at that time, ME 3, and it was cool. After playing that game I concluded it would have been better to play the 1 and 2 first but it was too late by then.
About TES, I never played Oblivion :[ The only experience I had with RPGs when first playing Skyrim was only with Fable I believe... And Skyrim was much bigger and better in every way. Plus, the mods are so cool. You should try Enderal if you have the time btw. Absolutely a top-notch game, some people say it was even better than Skyrim itself but for me it was equal. With games such as TES mods are like half the fun.
Yea ME1 was kinda stretch and i totally udnerstand where youre coming from. But...let me assure you taht youre TOTALLY WRONG thinking that it is not worth it to play ME2 as standalone game:)