7. Invasion! - Various (1996)
Much like buses, fans waited and waited for a Kirk/Picard crossover only for two to arrive at once. In 1994 released just one month before Generations, technically Federation was the first crossover novel, but in terms of trendsetting milestones this one-off story was overshadowed just two years later. As part of Star Trek's 30th anniversary, the Invasion! miniseries featured the crews of all four live-action series, who all shared a single narrative. The story spans four separate novels (the omnibus wasn't released until 1998), and First Strike, The Soldiers Of Fear, Time's Enemy, and The Final Fury each detail a separate incident involving an alien race known as The Furies. Spread out across two centuries and thousands of light years however, this was so much more than just the same story told in four different ways. After the initial threat against the Federation, Klingons and Romulans, Picard and his crew must deal with weapons both physical and psychological, Sisko is faced with an enigma in which his future is somehow connected to the furies' past, before Janeway finally takes the fight back to the Furies themselves. Dealing with suicide missions, temporal paradoxes and genocide, it is no wonder Invasion!'s example of what Star Trek crossovers could be was soon followed. Not all subsequent mini-series lived up to this high standard though, both the Double Helix and Gateways series were victims of bad marketing decisions, but the Section 31 novels were 2001's best sellers.