The LT-40 is generally regarded as the best overall trainer, but you really can't go wrong with any of the more common trainers, including the Goldberg Eagle 2, Hangar 9 Alpha, Tower Trainer, Telemaster, etc...

The Nexstar is very popular, but I believe that it is overpriced and over-gadgetted.

A very good combo is the Sig LT-40, with an OS 46AX, and a good 6-channel 2.4gHz radio system.

A good budget combo would be a Tower Trainer with an OS .46LA, and an entry-level radio. You could also save a few bucks by going with a Magnum, Super Tigre, or GMS engine, but they can be trickier for a beginner to keep tuned.

The easiest bet is to buy a RTF package, like the Hangar 9 Alpha 40 DSM2 package. You get everything you need for about $300.

There are a lot of options, but don't worry too much about it. They are all very good, and you will not regret buying any of them.

Good luck