2. ET - Star Wars Episode I: The Phantom Menace
It took George Lucas almost twenty years to repay Spielberg, but eventually he canonized the directors two movie universes; if the R2/3PO hieroglyphs were coincidence and the Han/Indy meet up outlandish, this is the crossover for you. With all the bells and whistles CGI offered George Lucas stuffed the prequels full of background references for fans to obsess over (well they needed to take something of worth from the trilogy). The senate was a golden opportunity for this, giving us hundreds of eclectic species. We got a little appearance from the Wookies, further canonization of the Grans after appearing in spin off titles for years and, most interestingly, ET. During Queen Amidalas call for a vote of no confidence you can clearly see a trio of aliens most certainly from the same species as everyones favourite small wrinkly alien (after Yoda of course). Already pretty cool, this one is made a little more interesting because theres a full fan theory behind it. When out on Halloween, ET spots a kid dressed as Yoda and immediately starts running towards them croaking home. Rather than being a sly product placement/cheap joke, could this retroactively turn ET into one of the promised Star Wars spin offs?