Raichu is a Poke we all want to be fanatstic. After all, if Pikachu is as heartbreakingly powerful as the Anime says, then surely its evolution must be incredible..! Well.. sort of. Raichu's great in PU and the lower tiers, not to mention VGC, but in Standard, it's kind of... eh. Not bad, exactly, but.. it just faces a ton of competition from more commonly used Electrics like Mega Manectric, Raikou, and even Jolteon (albeit the later in UU/RU).
+Base 110 Speed is incredible, especially for PU. You are (I believe) the eighth-fastest relevant Pokemon in PU, and even outrun a fair few things if you're brave enough to use it in OU (in which case, I salute you!)
+90/90 offenses aren't bad either, allowing you to hit specially or physically.
+Only one weakness in Ground means that it's not getting smacked by a supereffective move whenever it comes in.
+A decent movepool with Fake Out, Extreme Speed and Volt Tackle to name a few means it won't have trouble throwing together a set.
-Terrible 60/55/80 defenses mean it takes no supereffective hits and very few neutral physical hits.
-Only one weakness isn't as great as it seems when it's to Earthquake..
-Doesn't really hit hard enough without a boost from a Choice item or Nasty Plot. Wouldn't be too much of a problem on something bulkier, but something so frail needs to be able to OHKO most stuff to avoid the OHKO for itself.
-Competition is huge from other Special electrics like Raikou, Mega Manectric and Thundurus in OU and Zebstrika in lower tiers.
I would Raichu a pun here if I could think of one..
-Brick Break/ Focus Punch/ Iron Tail
Ability: Lightning Rod
252 Atk/ 252 Spe/ 4 SDef
Whilst this set is rather unorthodox and is probably best as an OO, it is very unexpected, and it's probably the closest thing to a niche you can get if you want to use 'Chu in OU, as there aren't too many physical electrics around. Volt Tackle is your standard attack, and the one you'll be using most of the time- it hits like a truck, with STAB, 120 Base power and Choice Band. Knock Off is another good attac, hitting Psychics and Ghosts slightly harder than VT and removing items. Extreme Speed deals with faster threats like Swellow, Scarf Jynx or a weakened Sceptile, as well as just being filler with decent coverage, but Return is available should you be unable to obtain the former. However, you should ONLY EVER use Return if you cannot get Extreme Speed, as the priority is far better than the extra power. Last set is whatever you want, really. Brick break could sorta be used in NU to slam a very weakened Steelix or Golem, but it's so weak that you might as well not bother on Rhydon, so it's pretty situational. Focus Punch is MUCH stronger, doing 52% at least to a standard tank Rhydon, but it's really, really situational. Iron Tail is a bit more useful than Brick Break against Golem and Rhydon, as well as Carbink (or Diancie in RU). Max Attack.. obviously, max Speed.. obviously, Jolly nature.. obviously, with the Choice Band to boost your Attack. Lightning Rod is the only ability for Raichu, really, as Static's not great when you faint to any contact move anyway.