I'm currently debating between Ground, Fire and Poison for secondary typings. When I look at the typing, I'm looking at an ability that can help dish out a lot of offensive damage or be a great defensive pokemon.
As Doug mentioned, Electric/Ground allows a lot of the top Pokemon to be KOed. However, Electric/Ground types lack very little coverage in moves. (not the two of them combined, mind you!) Electric types mainly get their STAB moves, Hidden Powah, the punches, and Grass Knot. Ground types mainly get Rock and Ground type moves. However, take these moves combined, and you can hit quite a bit of stuff. Ice Punch can come from the Electric typing to smack around Salamence. Focus Punch can also come in for a SubPunch set. The QuakeEdge combo can be abused, and it provides nearly unlimited coverage (only Skarm walls it IIRC). Electric/Ground can also make for a great mixed sweeper. T-Bolt/QuakeSlide/Grass knot anyone?
On the defensive side, Poison would help greatly for a defensive pokemon. Poison may add a 4x Ground and 2x Psychic weakness with Electric, but you also gain a Fighting resist and a Toxic Spikes absorber. Then again, we have one of those in Fidgit. The combination of Poison and Electric though allows for some great support holes to be filled. Thunder Wave and Toxic can cripple most teams, and can be easily put on an Electric/Poison type
An Electric/Fire type could also provide some great offensive coverage, since Electric and Fire complement each other well. Fire blows through the Grass-types that wall most Electric Pokemon, as well as Steelix. Electric decimates those Bulky waters that Fire-types might struggle with. Fire/Electric also allows for support, with moves like Will-O-Wisp, Sunny Day, Rain Dance (several electric types have that, no?) and Thunder Wave. Since an Electric/Fire Type can also function well in both Sun and Rain, there's a good shot that more weather teams will be used if Electric/Fire is used as the typing. This allows for an ability like Chlorophyll to be abused.
This probably just a lot of rambling ,since I'm fairly new to CAP. Feel free to criticize me in any way tat does not break the rules.
As Doug mentioned, Electric/Ground allows a lot of the top Pokemon to be KOed. However, Electric/Ground types lack very little coverage in moves. (not the two of them combined, mind you!) Electric types mainly get their STAB moves, Hidden Powah, the punches, and Grass Knot. Ground types mainly get Rock and Ground type moves. However, take these moves combined, and you can hit quite a bit of stuff. Ice Punch can come from the Electric typing to smack around Salamence. Focus Punch can also come in for a SubPunch set. The QuakeEdge combo can be abused, and it provides nearly unlimited coverage (only Skarm walls it IIRC). Electric/Ground can also make for a great mixed sweeper. T-Bolt/QuakeSlide/Grass knot anyone?
On the defensive side, Poison would help greatly for a defensive pokemon. Poison may add a 4x Ground and 2x Psychic weakness with Electric, but you also gain a Fighting resist and a Toxic Spikes absorber. Then again, we have one of those in Fidgit. The combination of Poison and Electric though allows for some great support holes to be filled. Thunder Wave and Toxic can cripple most teams, and can be easily put on an Electric/Poison type
An Electric/Fire type could also provide some great offensive coverage, since Electric and Fire complement each other well. Fire blows through the Grass-types that wall most Electric Pokemon, as well as Steelix. Electric decimates those Bulky waters that Fire-types might struggle with. Fire/Electric also allows for support, with moves like Will-O-Wisp, Sunny Day, Rain Dance (several electric types have that, no?) and Thunder Wave. Since an Electric/Fire Type can also function well in both Sun and Rain, there's a good shot that more weather teams will be used if Electric/Fire is used as the typing. This allows for an ability like Chlorophyll to be abused.
This probably just a lot of rambling ,since I'm fairly new to CAP. Feel free to criticize me in any way tat does not break the rules.