This has probably been done before...plus with so many variations of the G1 continuity, I'm just gonna leave out the weird alien ones from the Japanese continuity because they aren't even Transformers - and since Devil Z was the leader in Masterforce, Overlord isn't included for example. I'm also leaving out all the ones that were leaders for like five seconds *cough*Starscream*cough*. So let's look at our contestants and why they qualify! Galvatron: Duh. Whether you prefer his comic or cartoon version is up to you. Shockwave: Beat Megatron to a pulp and basically remained the leader of Decepticons on earth after Megatron disappeared, ceded when Megatron came back and then became the leader again when Megatron blew himself up. Oops. Ratbat: After Shockwave disappeared, being flung into the earth's atmosphere and all, Ratbat was more than happy to take over the Decepticon leadership on earth. Scorponok: Started off as the leader of Decepticon Headmasters, Targetmasters and Pretenders, leading his own faction rivaling Ratbat's "old" Decepticons, he became the leader of the whole lot after the latter was killed during the whole Underbase mess. Was a magnificent bastard in the Headmasters anime. Thunderwing: Appointed the leader by the Decepticon high council on Cybertron on the basis that he was crazy. See how well that went? Bludgeon: Became the leader for being the highest-ranking surviving Decepticon after the battle with Unicron, all the way up to Generation 2. Deszaras: Leader of the Decepticons during the Victory anime. Soundwave: Got his big break in the alternate future presented in the UK comics after everyone else either died or disappeared.