Way too many to list - but if my font purchasing habits are any indication then Christian Schwartz and Neil Summerour are at the top of the list. I have quite a few of their faces.

As Simon says - too many to list - so just some random picks: Kris Sowersby (National), Scaglione & Burian, and many of the designers at OurType including Smeijers (Ludwig and many other superb designs), Thiemich (Alto). Dan Reynolds' Malabar. Some of the work of Feliciano Type Foundry (Merlo, Rongel, Stella). Adrian Frutiger has done great work his entire career - more recently, new releases of classics like Univers Next and produced new designs such as Frutiger Serif. Gerard Unger is notable (Swift).

For broader surveys see Typographica's Favourites of 2008, and TDC Best of 2009 and 2008 - which gives you an idea of who's who, out there.

To me, Christian Schwartz because he consistently delivers outstanding designs, Ludwig Übele because his designs are much more ineresting than most stuff designed at the moment, Lucas de Groot simply because he designed TheSans, and Robert Slimbach, who has given us some of the most useful types available today. And, last but not least, Adrian Frutiger, the greatest master of all.

Fred Smeijers. One of the most versatile and inventive designers.
All his fonts are supreme, for instance I love Renard and Arnhem. And his classic Quadraat of course.

Giambattista Bodoni ;-)

Bram de Does (lexicon), Adrian Frutiger (Frutiger), Fred Smeijers (Quadrat).
Younger generation? Mmmhh... Nikola Djurek (Marlene).