Along these lines, I recently updated my franchise records for my two current prog teams. Guess I'll paste them here. These cover 1977-2005:
Atlanta Braves
PA: 803 Brett Butler 1993; 9281 Brett Butler career
AB: 721 Tom Paciorek 1981; 9281 Brett Butler career
R: 179 Chipper Jones 1999; 1562 Brett Butler career
H: 247 Tom Paciorek 1981; 2431 Brett Butler career
2B: 56 Jose Offerman 1999; 400 Dave Winfield career
3B: 16 Brett Butler 1985; 113 Brett Butler career
HR: 65 Andruw Jones 2005; 502 Dale Murphy career (8 different players with 50-HR seasons)
RBI: 205 Fred McGriff 1994; 1608 Dale Murphy career
BB: 159 Chipper Jones 1999; 1100 Brett Butler career
SO: 203 Gorman Thomas 1979; 1684 Dale Murphy career
HBP: 16 Jeff Blauser 1997; 69 Jeff Blauser career
SB: 36 Rafael Furcal 2005; 85 Rafael Furcal career (with only 3 career CS!)
CS: 12 Dave Winfield 1978; 20 Brett Butler, Shawon Dunston career (I don't like risking a CS, especially when my team can hit HR!)
AVG: .364 Chipper Jones 2001; AVG: .344 Tom Paciorek career (732/2131 AB)
OBP: .457 Chipper Jones 1999; .403 Chipper Jones career
SLG: .677 Fred McGriff 1994; .579 Bob Horner career
OPS: 1.106 Dale Murphy 1987; OPS: .957 Fred McGriff career
RC: 192.61 Fred McGriff 1994; RC: 1615.65 Dale Murphy career
GS: 55 Phil Niekro 1979; 633 Tom Glavine career
CG: 13 Phil Niekro 1978; 25 Phil Niekro career
SHO: 5 Phil Niekro 1978; 9 Phil Niekro career
W: 32 Tom Glavine 2000, Kevin Millwood 2000; 303 Tom Glavine career (8 different pitchers with 24-win seasons)
L: 26 Phil Niekro 1977; 182 Tom Glavine career
SV: 40 Steve Bedrosian 1984; 92 Doug Jones career
IP: 375 Phil Niekro 1979; 4084.2 Tom Glavine career
SO: 315 John Smoltz 1996; 2920 John Smoltz career
WHIP: 0.97 Jason Schmidt 2003; 1.23 John Smoltz career
ERA: 2.59 Jason Schmidt 2003; 3.67 John Smoltz career
Maybe the weirdest part of all those is that Dave Winfield holds my Braves' single-season record for caught stealing.
Seattle Mariners:
PA: 811 ichiro Suzuki 2004; 10257 Ken Griffey Jr.
AB: 753 Ichiro Suzuki 2004; 9006 Ken Griffey Jr.
R: 173 Ken Griffey Jr. 1999; 1892 Ken Griffey Jr.
H: 298 Ichiro Suzuki 2004; 2667 Ken Griffey Jr.
2B: 64 Edgar Martinez 1992; 539 Edgar Martinez
3B: 15 Tony Fernandez 1990; 62 Tony Fernandez
HR: 67 Ken Griffey Jr. 1998; 659 Ken Griffey Jr (7 50-HR seasons for Griffey, 5 50-HR seasons for other players)
RBI: 206 Shawn Green 1999; 2036 Ken Griffey Jr.
BB: 153 Edgar Martinez 1996; 1341 Edgar Martinez
SO: 183 Jim Presley 1986; 1668 Ken Griffey Jr.
HBP: 13 Edgar Martinez 1997, Tino Martinez 2003; 91 Ken Griffey Jr.
SB: 101 Dave Collins 1980; 242 Dave Collins
CS: 37 Dave Collins 1980; 74 Dave Collins
AVG: .396 Ichiro Suzuki 2004; .326 Ichiro Suzuki (min 1000 career hits); .317 Edgar Martinez (min 2000 career hits)
OBP: .472 Edgar Martinez 1995; .422 Edgar Martinez
SLG: .708 Ken Griffey Jr. 1993; .571 Ken Griffey Jr.
OPS: 1.147 Edgar Martinez 1995; .948 Ken Griffey Jr.
STRK: 47 Ichiro Suzuki 2004
RC: 205.97 Edgar Martinez 1995; 2006.58 Ken Griffey Jr.;
GP: 91 Dave Burba 1994; 683 Rick Honeycutt
GS: 50 Shane Rawley 1982; 499 David Wells
CG: 24 Ron Guidry 1978; 61 Ron Guidry
SHO: 5 Ron Guidry 1978; 10 Ron Guidry
W: 27 Erik Hanson 1990; 217 David Wells
L: 20 Rick Honeycutt 1979; 146 Ron Guidry
SV: 27 Bob Stoddard 1982; 63 Larry Andersen (I wonder if I overlooked someone)
IP: 340 Ron Guidry 1978; 3072 David Wells
SO: 294 Mark Langston 1987; 2152 Mark Langston
WHIP: 1.05 Mark Eichhorn 1986; 1.33 Derek Lowe (1017.2 IP)
ERA: 2.35 Mark Eichhorn 1986; 3.94 Derek Lowe (1017.2 IP)