Now I know there's enough of these threads.. probably bust I'll make one.  So here it goes. The PS2 data is from Video Game Sales Wiki. Wii sales are from Nintendo.       I'll do by the end of each fiscal year. Also I believe PS2 1st FY ending was Japan only.

1st FY   PS2- (1.41) 1.41         Wii- (5.84) 5.84

2nd FY  PS2- (9.20) 10.61       Wii- (18.61) 24.45

3rd FY   PS2- (18.07) 28.68     Wii- (25.54) 50.39

4th FY   PS2- (22.52) 51.20     Wii- (20.54) 70.93

5th FY   PS2- (20.10) 71.30     Wii- (15.08) 86.01

6th FY   PS2- (16.17) 87.47     Wii- (9.84) 95.85

7th FY   PS2- (16.22) 103.69   Wii- (3.99) 99.84

8th FY   PS2- (14.20) 117.89   Wii- (1.22) 101.06

Wii fell behind PS2 by having terrible legs. PS2 went to sell 155m units while Wii probably won't even hit 102m.

The Wii was a fun toy for some days, then it became a dust collecter.

PS2 4 Life

True... it collects dust while I play my GameCube or Wii U.

The PS2 was unmatched and the best console. However that poll will choose the Wii due to the numbers of Nintendo fans on this site. So no need to wait for the poll results.

the wii simply died fairly quickly. but other than that it was doing better for the first few years. ( 4 of them, so half)

Wii didn't have terrible legs so much as PS2 had really good ones. Wii's life was much like PS1's and other gen leaders before. Gen 7 was like two gens, where first people jumped from PS2 to Wii and then from Wii to PS360 when they (and HDTV's) became cheaper.

Tbf, the first year comparison is a bit distorted. PS2 was released in Japan a year early hence the low first 2 years compared to the Wii. OF course the Wii had a much bigger explosion, but no legs. It dramatically imploded in the end.

Sorry to go off topic but consoles that are used more actually collect more dust.  Those with larger fans are even worse.   Static electricity and low pressure systems are at work here.  

Just a peeve of mine that people claim the console they use least is the console that collects the most dust when the reality is the opposite.

Oh, and PS2 was easily the better console.  Far more rounded for players of all types.

Yeah Wii won't even reach PS1 numbers. Funny because in 2007 Ninty fans claimed it would sell 200 million.