Levels 1-20 : Go with the flow! Do the beginner quests and beginner job quests.
Levels 21-25 : Kerning City PQ
Levels 25-30 : Subway PQ (Use Dimensional Portal, and go to Construction Site.
(This PQ is like a min Pyramid PQ, only no difficulties, 3 rounds, and there's no huge skill like that big attack that kills everything.)
Levels 31-50 : Monster Carnival doing TW. Or just scam wins :P.
Levels 31-40 (OPTIONAL) : Pyramid Party Quest.
Levels 51-62ish : Mp3 in Singapore. On 2x.
Levels 63- 72ish : Lower Ascent, mob Wind Raiders. (WARNING: VERY HARD TO GET THERE!!)
Levels 73-80 : Twisted Jesters; 4x EXP card.
Levels 81-90 : Fight Balrogs to Witch Bear and you get alot of xp.
Mushroom Shrine Japan is a good place to train for lvl 24, New Leaf City is a good place too or in kening city construction site, go to the top where there's octopuses, go thru the portal there into a place where it is filled with octopuses with safe spots: CRAZY XP!
it all depends on what lvl you are.You can find out which level shuld train where on sleepywod.net but i also recommend these pq's for your level
Henesys pq lvl 10-20
Ariant pq 20-21
Kerning City pq, sleepywoods lvl 21-30
sleepwoods30-40
mcpq1 40-50
Sleepwoods(golems) 51-60
mcpq 61-70
Blank
neo city 75-80
Romeo/Juliet pq lvl 71-85
86-110 Leafre
111-200 Timeless temple
Some server has Silver Slime the Best(lvl 1-250)
blue ribbon pigs, got to level 30 in a flash, it is in the right of nautilus, the pirates place you know? anyway keep on going right
it depends what level your Roselia is. if it is higher than 40 it would be good to train it at the elite 4 if it is below level 40 it is good to train it anywhere with a EXP share.
Nowhere.
The best spot to train hunter in is the Feldip Hills as it can support your hunting to level 45.
easy route 26 kanto johto
turn back cave, mt.stark
you can either kill monsters around your level and do quests that give you good xp
Perion/Sleepywood.
give beautifly exp share and take him/her to the elite four and train there.
In Pokemon Diamond, a very good place to go is North of the Fight Area. All of the many trainers have level 45-60 Pokemon.
mt.silver is a good place because it has lvl.50 pokemon there
A good place for a level 76 is in the Stronghold of Security. On the first level, go to the treasure room, take the south exit out of that room, then keep going until you get to a room with level 27 minotours. This is a great place to train. There are also level 11 wovles there if you know someone weaker.