Assault: Hauberk - it's showing its age and is perhaps no longer the best performing, but the Hauberk set the standard of long range fire support suits. With mixed suits under consideration, the Fenrir II is very good, but quad, therefore sucks.
Heavy: Taranis - it was tough to decide between this and the Grenadier II, as both perform so well, but I do love the Mimetic/DWP combo, plus the Grenadier II is disgustingly filthy. Depending upon the day I'm asked, I could easily opt for the flexibility of the Grenadier II instead.
Medium: Cavalier II - unfair, because the majority of you won't know its stats, but [borat]is nice[/borat]. If I was to avoid Clantech, I'm split between the Amazon and Infiltrator Mk II in terms of performance and concept. Both have their cosmetic issues, but overall I prefer the looks of the Infiltrator Mk II.
Light: Achileus - older than the Hauberk, but who cares, it's still excellent.
PA(L): Nighthawk - because it was the first and I could use them in the Star League era against the rebel scum.