I love to peruse agent's blogs to see what in particular they are looking for.
Kathleen Ortiz is looking for YA, MG, and adult fiction.
YA: romances with a male POV, cyberpunk, thriller, historical romance (not WWI, WWII, medieval), apocalyptic (not pre or post)
MG: adventure, travel, boy book, something with a technology slant, steampunk
Adult romance (paranormal, urban fantasy, contemporary)
Jessica Faust is looking for steampunk, historical mysteries, contemporary romance, big fantasy romance, historical romances, and dystopian. She is still looking for great mysteries, romances, fantasy, women's fiction as well, but the first list is what she's most excited to read right now.
Jill Corcoran is looking for romance, especially romantic comedies, original paranormal MG and YA, MG about middle school (7th-8th grade), literary with a commercial hook, and commercial with literary prose.