I loved Malaysia and especially a little town called Melaka, great country and some of the best food I ate on my travels although not cheap for rooms or to have a beer!!! KL is a great City as well with loads of stuff to do free/cheap.
My brother and his missus have recently returned from Thailand and say it's not as cheap as it used to be as they have now brought in a minimum wage (about £6 a day!!!) that has bumped a lot of the prices up! Still cheap enough though and especially the further North you go! Again, if you go up to Chiang Mai (I lived there for 2 months and would definitely recommend it) then also get yourself to Pai which is one cool little town.
Don't know what your plans are but I would certainly put Cambodia and Laos on your list. Especially Cambodia which is my favourite country in SE Asia. And although I didn't have the best of times in Vietnam, for various reasons, it is certainly worth visiting for the history...............and it helps that some of the women are fit as fuck!!!
Enjoy and keep us updated on here from time to time if you can as I love hearing peoples travelling stories!! But don't come back with dreadlocks. Or a tattoo. Or a Thai bride.