I swing A Garrett GTI 1500. I just got back into the hobby from a 20 year layoff. I haven't gotten out much since I bought it a couple of months ago, but when I do I always find stuff. In the past I have owned a Fisher 1220X, Compass X80 Challenger and a Garrett X10 Workhorse. I like the 1500 that I have now, but knowing the gadget guy that I am I will probably branch out to other brands.
When it comes to any detector I think you will find research is the biggest investment of time when it comes to detecting. It's importent to know the area you intend to hunt, leastways it is for me. I have to maximize the time I do get to get out. I don't want to waste it at random areas. I guess that's why my detector is with me all the time.