I am trying to decide between a isengard or a modor based army, i could do a allied one but wouldprefer not to, any tips or good lists anyone know of??

You mean competitive lists? Check out my blog for the GT winning lists between 2004 - 2011 (2009 had Mordor, Harad and Harad, 2010 had top Mordor, Isengard and Moria in top 3, while 2011 had Harad, Mordor, Nazgul in top 3)

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Coordinator of the Great British Hobbit League

Isengard is a very elite army, boasting the strongest troops in the game. Mordor can be used as an elite army (although probably not as elite as Isengard), but is more often a horde army. Mordor has a lot more variety than Isengard and is a very versatile army.

Uruk-hai can be quite quick to paint, as they're all pretty much the same. Orcs, on the other hand, take a while to paint as each model has different clothing and armour. Some people like this variety, however, as it can be tedious to consistently paint the same.

And, by the way, Mordor and Isengard can't actually ally (if you use LoME).

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"There are few left in Middle Earth like Aragorn, son of Arathorn." - Gandalf, Many Meetings