That statement is just so wrong smoke started comming out of monitor.
May I recommend Timesplitters 2 - you may have on another format anyway, but if you haven't there it is.
F-Zero is an absolute must-have. Totally wipes the floor with Wipeout. Wario Ware is the ultimate party game, but if you must get Mario Party only get MP5. MArio Sunshine is superb, as is Metroid and the Pikmin games. Skies of Arcadia is also worth a spin, even if you don't like RPGs. Hitman 2 remains the best in the series so far in my opinion, and it's ludicrously high-action brother Freedom Fighter is boundless fun.
Phantasy Star Online is a must have if you have a couple of willing mates, even without any actual online mode.
I would also like to recommend Metal Arms - Glitch in the System. Definitly worth trawling for on Ebay. Barely anyone bought it, which is a damn shame as it's one of the best shooters on GC. Challenging, fabulous game.