A lot of people like Sandler movies and they make big money. This answer your questions about why he makes so many.
Happy Gilmore is way to low and Jack and Jill and Mr. Deeds are way to high.
Rank Title (click to view) Studio Adjusted Gross Unadjusted Gross Release
1 The Waterboy BV $270,948,200 $161,491,646 11/6/98
2 Big Daddy Sony $254,874,000 $163,479,795 6/25/99
3 The Longest Yard Par. $195,367,600 $158,119,460 5/27/05
4 Anger Management SonR $178,161,700 $135,645,823 4/11/03
5 Mr. Deeds Sony $172,159,100 $126,293,452 6/28/02
6 Click SonR $166,085,000 $137,355,633 6/23/06
7 Grown Ups Sony $161,389,900 $162,001,186 6/25/10
8 50 First Dates Sony $154,201,600 $120,908,074 2/13/04
9 I Now Pronounce You Chuck and Larry Uni. $138,208,100 $120,059,556 7/20/07
10 The Wedding Singer NL $135,510,900 $80,245,725 2/13/98
11 Bedtime Stories BV $121,449,500 $110,101,975 12/25/08
12 You Don't Mess with the Zohan Sony $110,327,200 $100,018,837 6/6/08
13 Just Go With It Sony $103,814,600 $103,028,109 2/11/11
- The Animal SonR $80,799,500 $57,743,062 6/1/01
- Zookeeper Sony $80,158,400 $80,360,843 7/8/11
14 Jack and Jill Sony $75,010,500 $74,158,157 11/11/11
15 Happy Gilmore Uni. $69,567,200 $38,824,099 2/16/96
16 Little Nicky NL $57,937,100 $39,464,775 11/10/00
17 Funny People Uni. $55,052,500 $51,855,045 7/31/09
18 Spanglish Sony $53,779,600 $42,726,869 12/17/04
- The Hot Chick BV $46,942,100 $35,081,594 12/13/02
19 Billy Madison Uni. $46,589,100 $25,588,734 2/10/95
- Coneheads Par. $40,699,500 $21,274,717 7/23/93
20 Bulletproof Uni. $38,662,800 $21,576,954 9/6/96
21 Eight Crazy Nights Sony $32,136,300 $23,586,598 11/27/02
- Deuce Bigalow: European Gigolo Sony $27,676,900 $22,400,154 8/12/05
22 Punch-Drunk Love SonR $24,324,600 $17,844,216 10/11/02
23 Reign Over Me Sony $22,634,100 $19,661,987 3/23/07
- Dirty Work MGM $16,926,300 $10,023,282 6/12/98
24 That's My Boy Sony $15,456,000 $15,456,001 6/15/12
Lifetime Gross Total (26): $2,062,066,438
Average: $79,310,248
Opening Gross Average (25): $24,247,393 (Wide Releases Only)