2014 models:

Sony Xperia™ M2
Model name: Xperia™ M2
Project name: D2303/2305/2306
Codename: Eagle
Sony Xperia™ T2 Ultra
Model name: Xperia™ T2 Ultra
Project name: D5303/5306
Codename: Tianchi
Sony Xperia™ Z2
Model name: Xperia™ Z2
Project name: D6502/6503/6543
Codename: Sirius
Sony Xperia™ E1
Model name: Xperia™ E1
Project name: D2004/2005
Codename: Falcon

2013 models:

Sony Xperia™ Z1 compact
Model name: Xperia™ Z1 compact
Project name: D5503
Codename: Anami

Sony Xperia™ M dual
Model name: Xperia™ M dual
Project name: C2004
Codename: Nicki DS

Sony Xperia™ Z1

Model name: Xperia™ Z1
Project name: C6902
Codename: Honami

Sony Xperia™ M

Model name: Xperia™ M
Project name: C1904
Codename: Nicki SS

Sony Xperia™ C

Model name: Xperia™ C
Project name: C2305
Codename: Pelican

Sony Xperia™ Z Ultra
Model name: Xperia™ Z Ultra
Project name: C6833
Codename: Togari

Sony Xperia™ ZR

Model name: Xperia™ ZR
Project name: C5502
Codename: Dogo

Sony Xperia™ L

Model name: Xperia™ L
Project name: C2105
Codename: TaoShan

Sony Xperia™ SP

Model name: Xperia™ SP
Project name: C5302
Codename: HuaShan

Sony Xperia™ E

Model name: Xperia™ E
Project name: C1505
Codename: NanHu SS

Sony Xperia™ ZL

Model name: Xperia™ ZL
Project name: C6502
Codename: Odin

Sony Xperia™ Z

Model name: Xperia™ Z
Project name: C6602
Codename: Yuga

Sony Xperia™ E dual
Model name: Xperia™ E dual
Project name: C1605
Codename: NanHu DS

2012 models:
Sony Xperia™ V

Model name: Xperia™ V
Project name: LT25i
Codename: Tsubasa

Sony Xperia™ J

Model name: Xperia™ J
Project name: ST26
Codename: JLo

Sony Xperia™ T

Model name: Xperia™ T
Project name: LT30p
Codename: Mint

Sony Xperia™ TX

Model name: Xperia™ TX
Project name: LT29
Codename: Hayabusa

Sony Xperia™ miro
Model name: Xperia™ miro
Project name: ST23
Codename: Mesona

Sony Xperia™ tipo dual
Model name: Xperia™ tipo dual
Project name: ST21i2
Codename: Tapioca dual

Sony Xperia™ SL

Model name: Xperia™ SL
Project name: LT26ii
Codename: Nozomi2

Sony Xperia™ tipo
Model name: Xperia™ tipo
Project name: ST21
Codename: Tapioca

Sony Xperia™ acro S
Model name: Xperia™ acro S
Project name: LT26w
Codename: Hikari

Sony Xperia™ ion HSPA
Model name: Xperia™ ion HSPA
Project name: LT28h
Codename: Aoba

Sony Xperia™ go

Model name: Xperia™ go
Project name: ST27
Codename: Lotus

Sony Xperia™ neo L
Model name: Xperia™ neo L
Project name: MT25
Codename: Phoenix

Sony Xperia™ ion LTE
Model name: Xperia™ ion LTE
Project name: LT28i
Codename: Aoba

Sony Xperia™ U

Model name: Xperia™ U
Project name: ST25
Codename: Kumquat

Sony Xperia™ P

Model name: Xperia™ P
Project name: LT22
Codename: Nypon

Sony Xperia™ sola
Model name: Xperia™ sola
Project name: MT27
Codename: Pepper

Sony Xperia™ S

Model name: Xperia™ S
Project name: LT26
Codename: Nozomi

Other codenames you can see here:
http://semcblog.com/other_codenames/