Although it might seem like a novelty set, I've had very positive experiences of using a special tanking Jynx with Wish in the 3rd generation and it might still not only be fun, but also good to use in 4th gen.
Jynx @ Leftovers
Timid/Calm Nature
EVs: 216 HP, 42 SAtk, 252 Speed
- Ice Beam / Psychic / Hidden Power [FIRE] / Focus Blast
- Wish
- Light Screen
- Lovely Kiss
Please note that the EVs are most likely off because I currently don't have access to my old Netbattle teams because I don't have the program installed.
One of the most overlooked qualities of Jynx is its base 95 Sp.Defense, which, with Light Screen support will be plenty for taking special hits. Not only that, but Jynx's Speed allows it to outrun quite many common threats and put them to sleep, giving you time to set up. Ice Beam is a nice offensive move even with light investment in Sp.Attack and will keep the Dragons away and Hidden Power [FIRE] will hurt Forretress and Skarmory. Focus Blast works for Tyranitar and Psychic is really only there for the sake of STAB and dealing a nice amount of damage to Heracross if it's brave enough to switch in on Jynx. I ran this set with Reflect support and it even took physical attacks surprisingly well despite its mediocre HP and downright bad Defense.
Yes, the set may seem random, but that's what they said about my Exeggutor with Wish, Reflect/Explosion, Leech Seed and Hidden Power [FIRE]. And yes, I loved experimenting with Wish back in 3rd gen.