The slayer is fun. Depending on what you want to do. If you're burning down the mall parking lots after dark or chasing the neighbors dogs, Slayer, T- Maxx or Revo are cool too. If you're considering putting one on a dirt track I would recommend saving your money and looking into a buggy or truggy. Much more durable and dirt worthy. If you're gonna stick to concrete and the backyard, the above mentioned are a blast! If you want to be even mildly competitive, go with the buggy or truggy. My 5 cents worth. Wish I would have done it that way. I went thru 3 T-Maxx's, 1 Slayer and a Revo before going buggy and truggy. Do the math. Although I do miss the days of mall parking lot bashing.
There are lots of good ones out there. Losi's are good, parts readily available at most houston area hobby shops. Mugen is my personal favorite, parts available everywhere. X-ray is really good too, a little more expensive to maintain. Associated makes good equipment - Depends on who you talk to. I've recently switched from Losi to Mugen and I love it. Best thing you can do is visit the local tracks and talk with folks, maybe test drive one of theirs and compare for yourself.
Ok, if you're gonna be out in the fields and just "Bashing" drag racing not much track time. Revo, sticking with Traxxas. Revo is all you need to look at, truck has the most versatility. Racing, Bashing, Crawling, Dragging, anything you want to do with it, you can. Just research the area and there are parts and set-ups to find.
Now if you plan on racing. Go with a Losi, AE, or Mugen. Mugen seems to have the most local support so, I would suggest a Mugen. Agama is a new kid on the block and look very promising. I would give it try not too expensive either. Not much local support but that may change with time.
I would say Buggy over Truggy but, Truggies are easier to drive.