I know this is rmt but i have a coulpe movesets for...

[Dr. Zafs]

Tangela!!!

Tangela
(sry i cant do evs i just suck at them)
hp fire
solarbeam
sunny day
leech seed

or

(again no evs)
leech seed
toxic
giga drain
rest

im sry but im not all that good but tell me what you think

 

[Brown Bomber]

Sleep Powder > Leech Seed on the first set, Sleep Powder and HP Grass > last two moves on the second set.

 

[SapphireL]

Tangela won't really have time to rest. >_>; 's Sp.Defense just sucks. >_<;

Try somethin' like a Modest Nature. :/ The first set imo is better.

 

[Pax Deorum]

Definetly use the first set, only with Sleep Powder over Leech Seed as stated in previous replies. Fore the spread give it like 159 Speed (stat) so it outspeeds Plusle/Minun after Sunny Day, Max Sp. Attack and put the rest in Defence.

I sometimes use Stun Spore over HP Fire on the first set since I've always liked Double Powder.