If you didn't know, Mecha is my favorite Anime genre and here are my reviews of two of the hottest Mecha animes on the scene at the moment.
Name: RideBack
Studio: Madhouse Studios
Genre: Mecha, Sports, Rebellion
Episodes: 5
Rating: 5

At the moment (excluding Hajime no Ippo - New Challenger) this is my favorite new anime. The fact that is a mecha anime is only a fringe benefit. I have no doubt that I would watch anyway even if there where no mecha in it.
And on that note, the mecha in this show are very low key actually. The story revolves around a former ballet protege Ogata Rin who suffers a career threatening injury while she is stil young. When she starts at high school (ateast I think its high school) she stumbles upon the schools RideBack club.

A RideBack is a mix between a robot and a motorcycle in that it has two wheels over which the rider straddles but in addition it also has two robotic arms which can and are used for many diferent purposes, ranging from balance to carrying weapons.
The main character joins the club for the reason that it lets her feel the same way she felt when she still did ballet, that being said, the modus operandi of the club is for sporting uses of RideBacks. There are however other organisations which make other uses of RideBacks and it isnt to soon before the RideBack club crosses paths with these other such organisations.
As I said before the story revolves around Rin, but she meets many characters during the first few episodes, some of whom are keeping some dark secrets. The story appears to be developing into strong political story and altough not factual, the story is unfolding in a very believable way.
The action sequences accompanied by some great music are very entertaining and some of the RideBack sequences bring memories of scenes from Air Gear, they are so graceful. A detachment from some of the mainstream mecha anime in two ways; it has a more femine feel to it and as an engineering friend of mine has pointed out, it is much more theoretically possible than other mecha animes.
I have thoroughly enjoyed the show thus far and eagerly await the next episodes.
Name: Vipers Creed
Studio: Sony Pictures Entertainment (Japan)
Genre: Mecha, Police, Sci-Fi, Capatalism
Episodes: 2
Rating: 4

This new anime appears to follow the same formula as a few manga's I've read, whereby an elite division in a private military company takes on very dangerous missions for the reward of extra money/profit. I however, with the expcetion of GITS, have not seen this in many mecha anime.
The elite unit Viper consists of a team of blademen who make use maneuver-blades (High-tech motorcycles) which have the ability to transform into different forms. Company policy states that each blademan needs to assisted by an operator who remains at headquarters and comunicates battle plans and news via radio, an interesting aspect of the story are the differing relationships between each blademan and their operator as some are good and others are non-existant.

The actions scenes are fast paced, with many of the enemy mecha's reminding me very strongly of those from one of my favorite animes - GITS. The 1st episode in particular is almost entirely one mission which they dive into immediately after the opening sequence. The story and character building only really start in the second episode.
The animation is very clean, with what appears to be a blue theme as most of the buildings are blue with all the computers being blue as well. Lots of high-tech future technology is displayed in the anime, but is done well and does not come off as unrealistic.
Unit Viper itself consists of many different character types which by on it own would make for an interesting anime, but i get this feeling that there is going to be a lot more to this anime.