Don't you know Ludicolo has been proven by scientists to be a good lead without rain? as for my favorite lead, it's... Crobat. :D I bet nobody would have been able to guess THAT. With his speed, and typing, it's very easy to predict what the opponent will do, especially since most opponents expect taunt on a lead bat.
I personally love using Genosekuto as a lead, but my fav is Armaldo. It is bulky as hell and i havent been OHkod untill now (no Sash). He can spin and set up rocks, and with his attack, launch some STAB furreh
Gen 4: best lead will always be specs heatran Gen 5: I love me some Genosekuto, but also Nattorei, and the lovely Dragonite ;D
DP OU: Bronzong DPP OU: Heatran DPP UU: Omastar DPP Ubers: Groudon BW: It all depends on your opponent's team.
I was probably the first to use Genosect leads (I used it in the very first Gen 5 testing, before the system corrupted and we had to go back to Gen 4 for months), and I still use it nowadays. It's evolved somewhat (no more LOLEXPLOSION), but it gets the job done better than any other Scarfer. My favourite lead of all time, though, is Gen 5 UU Attacking lead Empoleon. It simply doesn't lose the lead game, and I've swept with it more times than I have with my Feraligatr. Seriously. I'm the only one using it (to my experience), which is nice as well.
Azelf and Aerodactyl are great, but Borutorosu has never failed me. Check out my set: Thor (Borutorosu) (M) @ Leftovers Trait: Mischievous Heart EVs: 252 SAtk / 252 Spd Modest Nature (+SAtk, -Atk) - Taunt - Thunder Wave - Grass Knot - Thunderbolt He cripples common leads, leaving them as set-up fodder for my Ninjask/Blaziken. Thunderbolt kills Azelf and Aerodactyl, and Grass Knot OHKOs Hippowdon and Swampert, while 2HKOing Tyranitar, who both Ninjask and Blaziken hate. 252 Spd EVs lets him outrun other Misc. Heart abusers who don't think they need to outrun anyone. Especially Erufuun.
I enjoy Gliscor. He sets up rain pretty fast, Stealth rocks, and can earthquake a T-Tar or Metagross. His main problem is he gets 1 shotted by almost every ice move, and swampert is a really common lead. Usually against Ice users I set up stealth rocks then send Jolteon out for the Rain Dance, unless it's Swampert in which case I dance with Gliscor, then bring out Ludicolo for the seed bomb.
Trying a Murkrow anti-lead in my UU troll team for now. :P It's effective when the opponent doesn't crit or freeze me, which happens more than is statistically probable. :(