I've got 8,776 Cubs cards from 51 different brands listed on a spreadsheet. A random number generator picked five cards, one each from the past several decades.
1950s / 1960s: Topps 1955 #179 Jim Bolger Sorry Jim, but you look more like a college engineering student than a ballplayer. After brief stints with the Reds in '51, '52, and '54, Bolger was traded to the Cubs and spent the entire season in Chicago. He was used as a utility outfielder and played in 64 games. He didn't hit much (.206), showed no power (0 HR) and didn't produce many runs (7 RBIs). That landed him back in AAA for 1956.
1970s: Topps 1975 Mini #175 Ernie Banks MVP I loved this subset back in 1975 because I got to see what all the different designs looked like over the year. This was as close as I ever came to seeing these really "old" cards. Back then I never imagined that I would one day own the actual 1958 card. Banks was a stud in 1958, playing in all 154 games, hitting .313 with 47 HR and 129 RBIs. And the team, they finished in 5th, 10 games below .500.
1980s: Donruss 1981 #588 George Riley This is from Donruss' first set in 1981. I like how they had George back up against the ivy. Donruss did have a lot of pictures taken at Wrigley in the '81 set, so props to them for that. Riley didn't pitch for the Cubs in 1981, he was released by the team at the start of spring training. Instead, he spent the season with the White Sox class A team in Appleton, Wisconsin.
1990s: Donruss Diamond King 1994 #5 Rick Wilkins The Cubs catcher had a career year in 1993, batting .303 (+33 points), slugging 30 HR (+22) and knocking in 73 runs (+51). That landed him on the Diamond King card in 1994. Today if a player has that sort of improvement, it lands him on the "What did he take" list. Whatever he took in 1993 he stopped taking in 1994. His average dropped a whopping 76 points, down to .227. Home runs dropped 23, from 30 to 7; and RBIs fell from 73 to 39. The Cubs gave up on him midway through the '95 season, sending him to the Astros.
2000s: Topps 2001 #623 Kerry Wood. The 2001 season was Wood's first complete season since his rookie year, 1998. He pitched well, winning 12 and losing only 6. His ERA was only 3.36 and he had 217 strikeouts in 174 innings.