Well first off, let me say asking at "WiiChat" if you should get a wii is like going to a Ford Dealership and asking if you should get a Mustang.
That said, no it doesn't have "blow you away" graphics and it's not going to be winning any beauty pagents, but (like the fat girl in highschool) it has INNER beauty..
It has the deepest gameplay and most intuitive control scheme of any console to date. But most importantly, it's fun to play. I have a 360 and good Gaming PC but my Wii is just the funnest system with the best games period.
As for "must haves":
WiiSports (Comes free with the system.)
WiiPlay (Comes with 8 games, and a free WiiMote.)
WarioWare (Very fun, and silly game, and it really introduces you to everything the wiimote can do.)
The system is $249 and comes with 1 wiimote, 1 nunchuck, and a copy of the game WiiSports (which is really fun in it's own right.)
New Games are between $39.99 and $49.99, but can go as low as $29.99 if they're ports (Like Resident Evil 4)
Additional WiiMotes are $29.99 and $19.99 for the nunchuck.
If you don't have a WiFi network in your house, you'll want to buy a USB adapter for $39.99 if you want to go online with you wii.