There are many for me, i cant mention all here, but i will list a few that has inspired me, encouraged me and convicted me throughout my sojourn.
Zac Poonen for one, I dont think I ever heard a sermon from him that in some way stirred me to seek the Lord somehow.
T.A Sparks, I think Sparks is one of the greatest gifts to the church in the last hundred years, I cant explain in words, you have to listen for yourselves.
Ravenhill, I think Ravenhill is the one that has inspired me the most to "live all out for God" so to speak.
Tozer for his radical and just plain truth preaching.
And Art Katz, for his preaching pierces through all that is false and fleshly and get right to the inner most thing, often realizing how little i have done or how little my any effort to live for Christ really is and leaves me with a sense that anything but the absolute surrendered life to the Lord is rubbish.
some others worth looking into are Keith Daniel, Paul Washer, Charles Leiter, Dean Taylor, Denny Kenaston , major Ian Thomas, Allan Redpath, Erlo Stegen, Wilkerson, Carter Conlon and Richard Wurmbrand
To name a few from the last century and still living
before that i could name a much longer list :-)
but one thing i have learned, is no amount of good teaching, however true it is, can substitute the Holy Spirits teaching, and even more important, nothing the Holy Spirit teaches you or shows you will be beneficial unless you live it in your daily life in obedience to God.
I find it is very easy for my flesh to substitute obedience for with the excuse "I listen to sound teaching, i have sound doctrine", those two are vital, but if not coupled with obedience they matter little.