AT&T Park (formerly known as Pacific Bell Park and SBC Park) has been the home of the San Francisco Giants since 2000. Their row end design is quite simple. Just the Giants SF cap logo with a diamond and crossing bats. With all of the name changes that the park has had, the team was quite fortunate to go with a team-centric design rather than the sponsor's name.
Chase Field (formerly Bank One Ballpark), like AT&T went with a team-centric design. With the park's name change and team identity changes since 1998, the "A" logo actually is still relevant and in use.
Coors Field has been the home of the Rockies since their third season in 1995. All of the stadium's seats are green except for one row in the upper deck which is purple (pictured). Coors' row ends utilize a modified version of the Rockies primary logo with the flying ball/mountain/arch.
When Dodger Stadium opened in 1962, the seats were the same color scheme as now but made of wood. Sometime in the late 70's early 80's the colors changed and the wood seats were replaced with plastic. Neither the first nor second generation of Dodgers Stadium seats had row ends. In 2006, the stadium's original color scheme was restored and with it the team added their "LA" logo to the row ends.
Of all the bad the McCourt ownership has brought to the franchise, if they did one good thing it was the color scheme restoration.
Opened in 2004, PETCO Park is the newest ballpark in the NL West. Like the others, it too has a cool row end design. Unlike the others though, PETCO's actually have the corporate sponsor's name on them.
Though the name of the company hasn't changed, Petco (corporation) recently announced a re-branding. In the past the company's name was always represented in all caps. In the new version, its all lowercase. As far as I know, the Padres haven't changed the ballpark logo (which features the "all caps" Petco wordmark) yet.