This place had been a staple for my wife and I when we first moved out here. Their chips and salsa are awesome! I would recommend getting their Espinaca con Queso appetizer but it seems like it has gone downhill a bit in the recent months. However, it is hatch chile season right now at Jalapeno's so I would recommend trying their Espinaca with chorizo and hatch chiles (a twist on their original year round Espinaca). It is a lot better than the original and even more addicting.
The service has been spotty in all the times we go there. If you want superb service, you might want to look elsewhere. However, their Happy Hour is fairly decent and if you want an early "dinner" go there for some appetizers and chips/salsa. I would recommend the Hatch Chile quesadilla with a side of their Inferno sauce (definitely not a place for the health food junkie). Their Cheese crisp is also excellent!
Entrees are good but I generally get the same thing every time so I can not comment on the rest of the menu.
Overall, I would recommend going at least once (esp now during hatch season), but sign up for their Inferno Club on line and get $5 off your first meal.