After going to the Battle Arcade several times, I got a streak of 73 battles. I'm surprise I got this far, because my team isn't that great, haha. I am a bit dissapointed I fell a little short of the top three, but I guess that's inspiration to keep trying. Anyway, here's my team...
Salamence (female) "Brutalanda"
EVs 232 Atk, 24 SpA, 252 Spe
Salamence works as a great lead, because of her speed and vicous attack stat. Her Special Attack is also good enough to OHKO many Steel, Grass, Bug, and occasionaly Ice types (if I stay in, that is.) She can take on most anything besides Ice types, which always loom. This is the reason that this next pokemon exists...
Milotic (female) "Milotisch"
EVs: 148 HP, 252 Def, 108 SpA
The wall of the set, Milotic boasts 198 HP, with 134 and 145 as her Defense and Special Defense stats, respectively. All except two Ice types fall against her, the two being Dewgong and Walrein since the two can easily Rest off the poison damage and hit back with OHKO moves. Milotic is meant to Toxic things teammates can't handle, and Recover in their face as they wither away, launching off Surfs and Ice Beams when she can. She works amazingly well, and few Pokemon stop her from running rampant. Unfortunately, there are Grass types that scare her, which lets my next Pokemon come in.
Scizor (male) "Scherox"
IVs: Shockingly, unknown
EVs: 32 HP, 252 Atk, 224 Spe
-Brick Break/ Substitute
The final Pokemon on the set, and in my experience the worst. I'm probably using him all wrong with this set, but when I get +6 Atk there is not alot that can stop him. I try to get him out on stuff that doesn't pose a threat because of either weak attacks, or relies on Leech Seed and Toxic. Scherox doesn't mind Leech Seed, because he can just Roost off the damage and rip through with +6 Bullet Punches. The only problem is, if he hasn't set up and Milotic is down, Fire types ruin him completely.
How I Lost: After trying to paralyze the team of Machamp, Medicham, and Infernape, I hit the button to put one of my Pokes to sleep. Thankfully, it was Milotic, which can take hit thanks to Marvel Scale. I switch in Milotic immediately, and took Machamp's Ice Punch. Then Dynamicpunch. I only took about 50 damage, but then came a crit and I was brought down to the red! I woke up, and killed myself in confusion. I know this game is lost, so I bring in Salamence to Outrage. It doesn't OHKO, but neither does Ice Punch. Next turn I kill Machamp. In comes Infernape, which Fakes me Out to kill. Scizor has no chance. Fire Punch kills. Game over.
So there's my team, that has done quite well at the Arcade. I may prune off Scizor and find something that could work better, but this team has done a good job so far :D
Oh, and some proof of the streak... http://img697.imageshack.us/i/21302355.jpg/