There are many reasons why Wrigley Field is famous. One, is because of the age of the field, as it was built in 1914. It is the second oldest ballpark. Also, most of the original construction is still intact.
Wrigley Field was also where Babe Ruth allegedly called his home run shot.

There is just too much information for me just to tell you why the park is so popular. Check out some of these sites if you would like to know more:

Wrigley field is so popular for a few reasons. One, it is the most beautiful park in the world. I've been to several, and all have their own charm, but Wrigley is by far the most beautiful.

Two, the crowd is unbelievable. We will cheer for the Cubs no matter what...like not going to the Series for 100 years. They still love their team and its incredible to be there.

Third, it is one of the only parks that has not been redone, torn down and rebuilt. It is the exact same park, therefore it holds a historic quality that few parks do. It spans generations like few other parks do. I believe the only other two are Yankee Stadium and Fenway, as far as the original buildings.

Wrigley field is a park that anyone who has an appreciation for baseball should visit. Simply put...spectacular.

Being from Chicago, and being a Sox fan, I feel compelled to answer.

Wrigley Field is located in Wrigleyville, which is just north of Lincoln Park, where DePaul University is. There are 100+ bars in the area directly surrounding Wrigley. Cubs fans have the reputation of being drunken buffoons and partygoers that only go to Wrigley because of the bar scene. Although Wrigley is a great place to watch a baseball game, regardless of how good or bad the Cubs are, the popularity of Wrigley has more to do with the atmosphere than the actual team. Cubs fans will say otherwise, and some of them probably are true fans for whom this is accurate, but the majority are just college kids and twentysomethings looking to have a good time.

Wrigley has been around for a long time. The Bears played there for some years, and up until 8-8-88, the Field didn't have lights, so all the games were in the afternoon. There's also the ivy, but you proabably knew that. It's one of the few venues that has changed very little since it was built, and it's close to landmark status.

The popularity of Wrigley Field is a little overblown in historical terms. There were periods of times in the 60's and 70's where the ballpark was practically empty, save a few of the original 'bleacher bums'. The current popularity has a lot to do with the 1980's - Harry Caray and the WGN network in particular. Harry turned Wrigley into more than a baseball park; it was a place to kick back, get drunk, and have a great afternoon. That, coupled with WGN bringing the games to most of the nation, created a very large fan base. The beautiful backdrop with the ivy walls, old-school scoreboard, and middle-of-the-neighborhood setting also makes a Cubs game feel like more of a block party than a mere game...of course I prefer to watch baseball games for the game itself, and not the drunken experience, so I'm not totally in love with the Wrigley vibe.

Half the seats have restricted views. There is poles blocking the views of a lot of seats.

I guess people like looking at poles better than the Cubs.

It's just a great place to watch a game. Every one loves the lovable losers