There are some games that I own and see people listing that I thought looked pretty bad.
Zelda SS looked pretty bad on anything except my daughter's tiny HDTV (19 inch, I think. It may be smaller.
Xenoblade looked horrendous to me. Still was fun, though.
The Last Story looked pretty decent but nothing special.
Endless Ocean looked pretty bad.
Other M looked really good at times and really bad (almost PS1 bad) at other times.
I can only comment on games I've actually played, though. I know first hand that screenshots lie. I have my PC connected to the same HDTV that I game on and the screenshots look better on the PC than they do actually running on the console.