I love M13 myself in my Z10. It's best when the power is cranked up, 7mm or 5mm Nagler, with a wide field of view and about 180x and 250x. I have also caught three quasars in it: 3C-273 in Virgo, at mag 12.5, Markarian 421 in Ursa Major, mag 13.1, and BL Lac in Lacerta, at an incredible magnitude 14.7 or dimmer. Another pretty one: M57 the ring nebula: I look for the dim stars around it as well, at mag 13 - 14.6. Polaris is always easy and always impressive to me, but I've also split some close double stars, Izar recently, with a 2.8 arcsec separation. In the Spring I split Porrima, 1.4 arcsec apart, both doubles very pretty.